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    <title>topic Re: Arcgis-JS-API 4.10 - Basemapgallery Error in ArcGIS JavaScript Maps SDK Questions</title>
    <link>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412239#M37978</link>
    <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hello Bjorn&lt;/P&gt;&lt;P&gt;Thanks for your answer.&lt;/P&gt;&lt;P&gt;Here is the sample code, which produces the error:&lt;/P&gt;&lt;PRE class="lia-code-sample line-numbers language-none"&gt;&lt;CODE&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;!&lt;/SPAN&gt;DOCTYPE HTML&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;html&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;head&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;meta charset&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"utf-8"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;meta name&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"viewport"&lt;/SPAN&gt; content&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"initial-scale=1, maximum-scale=1,user-scalable=no"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;title&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;BasemapGallery widget &lt;SPAN class="operator token"&gt;-&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;4.10&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;title&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;link rel&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"stylesheet"&lt;/SPAN&gt; href&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.10%2Fesri%2Fcss%2Fmain.css" target="_blank"&gt;https://js.arcgis.com/4.10/esri/css/main.css&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;style&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; html&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; body&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; #viewDiv &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; padding&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;0&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; margin&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;0&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; height&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;100&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;%&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; width&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;100&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;%&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;style&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;script src&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.10%2F" target="_blank"&gt;https://js.arcgis.com/4.10/&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="token function"&gt;require&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/Map"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/Basemap"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/views/MapView"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/widgets/BasemapGallery"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/widgets/BasemapGallery/support/LocalBasemapsSource"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/layers/WMTSLayer"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;function&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; Map&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; Basemap&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; MapView&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; BasemapGallery&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; LocalBasemapsSource&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; WMTSLayer
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; map &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Map&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; view &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;MapView&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; container&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"viewDiv"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; map&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; map
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; mapBaseLayer2 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;WMTSLayer&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; url&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fgibs.earthdata.nasa.gov%2Fwmts%2Fepsg4326%2Fbest" target="_blank"&gt;https://gibs.earthdata.nasa.gov/wmts/epsg4326/best&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; copyright&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fearthdata.nasa.gov" target="_blank"&gt;https://earthdata.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;Earthdata&amp;lt;/a&amp;gt; by &amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fwww.nasa.gov" target="_blank"&gt;https://www.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;NASA&amp;lt;/a&amp;gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; activeLayer&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"SRTM_Color_Index"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; mapBaseLayer1 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;WMTSLayer&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; url&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fgibs.earthdata.nasa.gov%2Fwmts%2Fepsg4326%2Fbest" target="_blank"&gt;https://gibs.earthdata.nasa.gov/wmts/epsg4326/best&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; copyright&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fearthdata.nasa.gov" target="_blank"&gt;https://earthdata.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;Earthdata&amp;lt;/a&amp;gt; by &amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fwww.nasa.gov" target="_blank"&gt;https://www.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;NASA&amp;lt;/a&amp;gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; activeLayer&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"SRTM_Color_Index"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="comment token"&gt;// Create a Basemap with the WebTileLayer. The thumbnailUrl will be used for&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="comment token"&gt;// the image in the BasemapToggle widget.&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; stamen &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Basemap&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; baseLayers&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt; mapBaseLayer2 &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; title&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test2"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test2"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; thumbnailUrl&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"icon"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; stamen1 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Basemap&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; baseLayers&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt; mapBaseLayer1 &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; title&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; thumbnailUrl&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"icon"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; basemapGallery &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;BasemapGallery&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; view&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; view&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;source&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt;stamen&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; stamen1&lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;activeBasemap&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; stamen
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="comment token"&gt;// Add the widget to the top-right corner of the view&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; view&lt;SPAN class="punctuation token"&gt;.&lt;/SPAN&gt;ui&lt;SPAN class="punctuation token"&gt;.&lt;/SPAN&gt;&lt;SPAN class="token function"&gt;add&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;basemapGallery&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; position&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"top-right"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;head&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;body&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;div id&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"viewDiv"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;div&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;body&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;html&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="line-numbers-rows"&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;/CODE&gt;&lt;/PRE&gt;&lt;P&gt;I hope this helps, for reproducing the error. The basemaps in the sample code come from an esri sample. (&lt;A class="link-titled" href="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=layers-wmts" title="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=layers-wmts" rel="nofollow noopener noreferrer" target="_blank"&gt;ArcGIS API for JavaScript Sandbox&lt;/A&gt;&amp;nbsp;)&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;regards&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
    <pubDate>Sat, 11 Dec 2021 18:42:46 GMT</pubDate>
    <dc:creator>SahanFaruk</dc:creator>
    <dc:date>2021-12-11T18:42:46Z</dc:date>
    <item>
      <title>Arcgis-JS-API 4.10 - Basemapgallery Error</title>
      <link>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412237#M37976</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hi all&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;We have upgraded our JS-Api from 4.7 to 4.10 , everything works fine, only some issues need to be fixed. But then we realize when starting our app the BaseMap Gallery Widget is not working any more.&amp;nbsp;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;Error happens when doing following steps:&lt;/P&gt;&lt;OL&gt;&lt;LI&gt;open widget&lt;/LI&gt;&lt;LI&gt;choose a basemap from the list&lt;/LI&gt;&lt;/OL&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;Result:&lt;/P&gt;&lt;P&gt;The basemap can not be loaded because of a classic null-pointer&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;Error from Browser log:&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt;ERROR Error: Uncaught (in promise): TypeError: Cannot set property 'visible' of null&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt;TypeError: Cannot set property 'visible' of null&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at Object.&amp;lt;anonymous&amp;gt; (MapView.js:603)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.callback (dojo.js:365)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.notify (dojo.js:325)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.propertyInvalidated (dojo.js:326)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.propertyInvalidated (dojo.js:298)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.callback (dojo.js:330)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.notify (dojo.js:325)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.propertyCommitted (dojo.js:327)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.propertyCommitted (dojo.js:299)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at b.internalSet (dojo.js:297)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at resolvePromise (zone.js:795)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at zone.js:847&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (zone.js:425)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at Object.onInvokeTask (core.es5.js:3881)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (zone.js:424)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at Zone.webpackJsonp.../../../../zone.js/dist/zone.js.Zone.runTask (zone.js:192)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at drainMicroTaskQueue (zone.js:602)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at ZoneTask.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneTask.invokeTask [as invoke] (zone.js:503)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at invokeTask (zone.js:1427)&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN style="font-size: 12px; color: #800000;"&gt; at HTMLLIElement.globalZoneAwareCallback (zone.js:1445)&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 15px;"&gt;&lt;STRONG&gt;Does anybody has already met this problem or a similar problem?&lt;/STRONG&gt;&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 12px;"&gt;regards,&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 12px;"&gt;Sahan&lt;/SPAN&gt;&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Wed, 09 Jan 2019 12:45:06 GMT</pubDate>
      <guid>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412237#M37976</guid>
      <dc:creator>SahanFaruk</dc:creator>
      <dc:date>2019-01-09T12:45:06Z</dc:date>
    </item>
    <item>
      <title>Re: Arcgis-JS-API 4.10 - Basemapgallery Error</title>
      <link>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412238#M37977</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hi Sahan,&lt;BR /&gt;I can't repro this with the basic sample at&amp;nbsp;&lt;A class="jivelink11" href="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=widgets-basemapgallery" title="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=widgets-basemapgallery"&gt;https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=widgets-basemapgallery&lt;/A&gt;&amp;nbsp;- even when changing to MapView as your error indicates.&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;Could you provide a simple sample that shows the problem?&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Thu, 10 Jan 2019 19:04:15 GMT</pubDate>
      <guid>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412238#M37977</guid>
      <dc:creator>BjornSvensson</dc:creator>
      <dc:date>2019-01-10T19:04:15Z</dc:date>
    </item>
    <item>
      <title>Re: Arcgis-JS-API 4.10 - Basemapgallery Error</title>
      <link>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412239#M37978</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hello Bjorn&lt;/P&gt;&lt;P&gt;Thanks for your answer.&lt;/P&gt;&lt;P&gt;Here is the sample code, which produces the error:&lt;/P&gt;&lt;PRE class="lia-code-sample line-numbers language-none"&gt;&lt;CODE&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;!&lt;/SPAN&gt;DOCTYPE HTML&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;html&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;head&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;meta charset&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"utf-8"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;meta name&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"viewport"&lt;/SPAN&gt; content&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"initial-scale=1, maximum-scale=1,user-scalable=no"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;title&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;BasemapGallery widget &lt;SPAN class="operator token"&gt;-&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;4.10&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;title&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;link rel&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"stylesheet"&lt;/SPAN&gt; href&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.10%2Fesri%2Fcss%2Fmain.css" target="_blank"&gt;https://js.arcgis.com/4.10/esri/css/main.css&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;style&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; html&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; body&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; #viewDiv &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; padding&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;0&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; margin&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;0&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; height&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;100&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;%&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; width&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="number token"&gt;100&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;%&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;style&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;script src&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fjs.arcgis.com%2F4.10%2F" target="_blank"&gt;https://js.arcgis.com/4.10/&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="token function"&gt;require&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/Map"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/Basemap"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/views/MapView"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/widgets/BasemapGallery"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/widgets/BasemapGallery/support/LocalBasemapsSource"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="string token"&gt;"esri/layers/WMTSLayer"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;function&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; Map&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; Basemap&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; MapView&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; BasemapGallery&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; LocalBasemapsSource&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; WMTSLayer
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; map &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Map&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; view &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;MapView&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; container&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"viewDiv"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; map&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; map
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; mapBaseLayer2 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;WMTSLayer&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; url&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fgibs.earthdata.nasa.gov%2Fwmts%2Fepsg4326%2Fbest" target="_blank"&gt;https://gibs.earthdata.nasa.gov/wmts/epsg4326/best&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; copyright&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fearthdata.nasa.gov" target="_blank"&gt;https://earthdata.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;Earthdata&amp;lt;/a&amp;gt; by &amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fwww.nasa.gov" target="_blank"&gt;https://www.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;NASA&amp;lt;/a&amp;gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; activeLayer&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"SRTM_Color_Index"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; mapBaseLayer1 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;WMTSLayer&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; url&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fgibs.earthdata.nasa.gov%2Fwmts%2Fepsg4326%2Fbest" target="_blank"&gt;https://gibs.earthdata.nasa.gov/wmts/epsg4326/best&lt;/A&gt;&lt;SPAN&gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; copyright&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;&lt;SPAN&gt;"&amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fearthdata.nasa.gov" target="_blank"&gt;https://earthdata.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;Earthdata&amp;lt;/a&amp;gt; by &amp;lt;a target='_top' href='&lt;/SPAN&gt;&lt;A class="jive-link-external-small" href="https://community.esri.com/external-link.jspa?url=https%3A%2F%2Fwww.nasa.gov" target="_blank"&gt;https://www.nasa.gov&lt;/A&gt;&lt;SPAN&gt;'&amp;gt;NASA&amp;lt;/a&amp;gt;"&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; activeLayer&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"SRTM_Color_Index"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="comment token"&gt;// Create a Basemap with the WebTileLayer. The thumbnailUrl will be used for&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="comment token"&gt;// the image in the BasemapToggle widget.&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; stamen &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Basemap&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; baseLayers&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt; mapBaseLayer2 &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; title&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test2"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test2"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; thumbnailUrl&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"icon"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; stamen1 &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;Basemap&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; baseLayers&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt; mapBaseLayer1 &lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; title&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; id&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"test"&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; thumbnailUrl&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"icon"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="keyword token"&gt;var&lt;/SPAN&gt; basemapGallery &lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt; &lt;SPAN class="keyword token"&gt;new&lt;/SPAN&gt; &lt;SPAN class="token class-name"&gt;BasemapGallery&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; view&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; view&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;source&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;[&lt;/SPAN&gt;stamen&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; stamen1&lt;SPAN class="punctuation token"&gt;]&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;activeBasemap&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; stamen
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="comment token"&gt;// Add the widget to the top-right corner of the view&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; view&lt;SPAN class="punctuation token"&gt;.&lt;/SPAN&gt;ui&lt;SPAN class="punctuation token"&gt;.&lt;/SPAN&gt;&lt;SPAN class="token function"&gt;add&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;(&lt;/SPAN&gt;basemapGallery&lt;SPAN class="punctuation token"&gt;,&lt;/SPAN&gt; &lt;SPAN class="punctuation token"&gt;{&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; position&lt;SPAN class="punctuation token"&gt;:&lt;/SPAN&gt; &lt;SPAN class="string token"&gt;"top-right"&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;SPAN class="punctuation token"&gt;}&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;)&lt;/SPAN&gt;&lt;SPAN class="punctuation token"&gt;;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;script&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;head&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;body&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&amp;nbsp; &lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;div id&lt;SPAN class="operator token"&gt;=&lt;/SPAN&gt;&lt;SPAN class="string token"&gt;"viewDiv"&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;div&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;body&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;
&lt;SPAN class="operator token"&gt;&amp;lt;&lt;/SPAN&gt;&lt;SPAN class="operator token"&gt;/&lt;/SPAN&gt;html&lt;SPAN class="operator token"&gt;&amp;gt;&lt;/SPAN&gt;&lt;SPAN class="line-numbers-rows"&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;SPAN&gt;‍&lt;/SPAN&gt;&lt;/SPAN&gt;&lt;/CODE&gt;&lt;/PRE&gt;&lt;P&gt;I hope this helps, for reproducing the error. The basemaps in the sample code come from an esri sample. (&lt;A class="link-titled" href="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=layers-wmts" title="https://developers.arcgis.com/javascript/latest/sample-code/sandbox/index.html?sample=layers-wmts" rel="nofollow noopener noreferrer" target="_blank"&gt;ArcGIS API for JavaScript Sandbox&lt;/A&gt;&amp;nbsp;)&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;regards&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Sat, 11 Dec 2021 18:42:46 GMT</pubDate>
      <guid>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412239#M37978</guid>
      <dc:creator>SahanFaruk</dc:creator>
      <dc:date>2021-12-11T18:42:46Z</dc:date>
    </item>
    <item>
      <title>Re: Arcgis-JS-API 4.10 - Basemapgallery Error</title>
      <link>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412240#M37979</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;This was filed as a bug:&lt;/P&gt;&lt;P&gt;&lt;SPAN style="color: #000000;"&gt;BUG-000119655&amp;nbsp; - Basemap Gallery Widget errors switching between WMTS basemaps.&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="color: #000000;"&gt;If anyone comes up with a workaround (other than using the JS API 4.9) that would be well appreciated &lt;span class="lia-unicode-emoji" title=":slightly_smiling_face:"&gt;🙂&lt;/span&gt;&lt;/SPAN&gt;&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Tue, 29 Jan 2019 12:31:54 GMT</pubDate>
      <guid>https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/arcgis-js-api-4-10-basemapgallery-error/m-p/412240#M37979</guid>
      <dc:creator>AndryJoos</dc:creator>
      <dc:date>2019-01-29T12:31:54Z</dc:date>
    </item>
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