I am using esri arcgis javascript 4.11 ,all the other things is walking but the LEGEND could not be added to the mapview this is the error "Export There seems to have been an error." is showing and all the layers are being added by clicking on checkbox.
<SPAN class="operator token"><</SPAN>script src<SPAN class="operator token">=</SPAN><SPAN class="string token">"https://js.arcgis.com/4.11/"</SPAN><SPAN class="operator token">></SPAN><SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>script<SPAN class="operator token">></SPAN>
<SPAN class="operator token"><</SPAN>script<SPAN class="operator token">></SPAN>
<SPAN class="keyword token">let</SPAN> view<SPAN class="punctuation token">;</SPAN>
<SPAN class="token function">require</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>
<SPAN class="string token">"esri/Map"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/views/MapView"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/WebMap"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/ScaleBar"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/BasemapToggle"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/BasemapGallery"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/FeatureLayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/PopupTemplate"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/Zoom"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/tasks/QueryTask"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/tasks/support/Query"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/Graphic"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/geometry/Geometry"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/core/Accessor"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/geometry/Extent"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/symbols/SimpleLineSymbol"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/SceneLayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/views/draw/Draw"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/geometry/geometryEngine"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/views/draw/PolygonDrawAction"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/support/Sublayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/ImageryLayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/MapImageLayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/renderers/UniqueValueRenderer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/Viewpoint"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/Legend"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/Print"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/widgets/Directions"</SPAN>
<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>Map<SPAN class="punctuation token">,</SPAN> MapView<SPAN class="punctuation token">,</SPAN>WebMap<SPAN class="punctuation token">,</SPAN>ScaleBar<SPAN class="punctuation token">,</SPAN>BasemapToggle<SPAN class="punctuation token">,</SPAN>BasemapGallery<SPAN class="punctuation token">,</SPAN>FeatureLayer<SPAN class="punctuation token">,</SPAN>InfoTemplate<SPAN class="punctuation token">,</SPAN>PopupTemplate<SPAN class="punctuation token">,</SPAN>Zoom<SPAN class="punctuation token">,</SPAN>QueryTask<SPAN class="punctuation token">,</SPAN>Query<SPAN class="punctuation token">,</SPAN>Graphic<SPAN class="punctuation token">,</SPAN>Geometry<SPAN class="punctuation token">,</SPAN>
Accessor<SPAN class="punctuation token">,</SPAN>Extent<SPAN class="punctuation token">,</SPAN>SimpleLineSymbol<SPAN class="punctuation token">,</SPAN>SceneLayer<SPAN class="punctuation token">,</SPAN>Draw<SPAN class="punctuation token">,</SPAN>geometryEngine<SPAN class="punctuation token">,</SPAN>PolygonDrawAction<SPAN class="punctuation token">,</SPAN>Sublayer<SPAN class="punctuation token">,</SPAN>ImageryLayer<SPAN class="punctuation token">,</SPAN>MapImageLayer<SPAN class="punctuation token">,</SPAN>
UniqueValueRenderer<SPAN class="punctuation token">,</SPAN>Viewpoint<SPAN class="punctuation token">,</SPAN>Legend<SPAN class="punctuation token">,</SPAN>Print<SPAN class="punctuation token">,</SPAN>Directions<SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="keyword token">var</SPAN> map <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Map</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
basemap<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"topo"</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
view <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">MapView</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
container<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"viewDiv"</SPAN><SPAN class="punctuation token">,</SPAN>
map<SPAN class="punctuation token">:</SPAN> map<SPAN class="punctuation token">,</SPAN>
center<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">85.0985</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">20.5</SPAN><SPAN class="punctuation token">]</SPAN>
zoom<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">8</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> scaleBar <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">ScaleBar</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
view<SPAN class="punctuation token">:</SPAN> view<SPAN class="punctuation token">,</SPAN>
unit<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"dual"</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
view<SPAN class="punctuation token">.</SPAN>ui<SPAN class="punctuation token">.</SPAN><SPAN class="token function">add</SPAN><SPAN class="punctuation token">(</SPAN>scaleBar<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">{</SPAN>
position<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"bottom-left"</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
view<SPAN class="punctuation token">.</SPAN><SPAN class="token function">when</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="keyword token">var</SPAN> featureLayer <SPAN class="operator token">=</SPAN> map<SPAN class="punctuation token">.</SPAN>layers<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getItemAt</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> legend <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Legend</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
view<SPAN class="punctuation token">:</SPAN> view<SPAN class="punctuation token">,</SPAN>
layerInfos<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN>
<SPAN class="punctuation token">{</SPAN>
layer<SPAN class="punctuation token">:</SPAN> featureLayer<SPAN class="punctuation token">,</SPAN>
title<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"test"</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="punctuation token">]</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
view<SPAN class="punctuation token">.</SPAN>ui<SPAN class="punctuation token">.</SPAN><SPAN class="token function">add</SPAN><SPAN class="punctuation token">(</SPAN>legend<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"bottom-right"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> roadsLayer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">FeatureLayer</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">{</SPAN>
id <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"roadLayerId"</SPAN><SPAN class="punctuation token">,</SPAN>
outFields<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">"*"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
popupTemplate<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">{</SPAN>
title<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"NAME1 : {xyz}:NAME: {XXXK}"</SPAN><SPAN class="punctuation token">,</SPAN>
content<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"TESTED"</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="token function">$</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"#chkRoadLayer"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">click</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">function</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="keyword token">if</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="operator token">!</SPAN>roadsLayer<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="keyword token">else</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="token function">$</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">this</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">is</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">":checked"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>
map<SPAN class="punctuation token">.</SPAN><SPAN class="token function">add</SPAN><SPAN class="punctuation token">(</SPAN>roadsLayer<SPAN class="punctuation token">,</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN> <SPAN class="keyword token">else</SPAN> <SPAN class="punctuation token">{</SPAN>
map<SPAN class="punctuation token">.</SPAN>layers<SPAN class="punctuation token">.</SPAN><SPAN class="token function">remove</SPAN><SPAN class="punctuation token">(</SPAN>roadsLayer<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="comment token">//XXXXXXXXXXXXXXXXXXXXXXXXXXXX</SPAN>
<SPAN class="comment token">//XXXXXXXXXXXXXXXXXXXXXXXXXXXX</SPAN>
<SPAN class="comment token">//XXXXXXXXXXXXXXXXXXXXXXXXXXXX</SPAN>
<SPAN class="comment token">//XXXXXXXXXXXXXXXXXXXXXXXXXXXX</SPAN>
<SPAN class="comment token">//XXXXXXXXXXXXXXXXXXXXXXXXXXXX</SPAN>
<SPAN class="comment token">//#other codes goes here</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="operator token"><</SPAN><SPAN class="operator token">/</SPAN>script<SPAN class="operator token">></SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>Robert Scheitlin, GISP