Vector Tile Packages not loading in ArcGIS Enterprise Web App

[IsobelMcLees]

I have several CAD drawings that I need to display in a Web App on our ArcGIS Portal. I have been using Vector Tile Packages as these seem to be the best in terms of performance. All Vector Tile Packages load fine in the Web Map but as soon as the Map is loaded into a Web App, the layers stop appearing. 

The only way I have found to get the layers to load in the App is if I clear my browser history but as soon as the App is refreshed, the layers disappear again so this is not a workable solution. 

I have even tried hosting the layers in ArcGIS Online and sharing across but this still doesn't work 

The vector tile packages have been published from ArcGIS Pro using the British National Grid Tiling scheme. Interestingly our other web App that are in WGS84 do not have the same problem? 

I am wondering if this is a known problem or if there is anything else I can do to get my layers to reliably load every time the app is open? 

[Brian_Wilson]

I would try generating standard Google/Bing style tiles and see what that does.

[IsobelMcLees]

Thank you for your response but this would mean my layers would be in WGS84 and I need them in British National Grid

[Brian_Wilson]

They all have to be in the same reference system, so you'd need to stop using anything not in British National Grid. That means you won't be able to use any Esri basemaps or most services everywhere... you will now bow down to The Google. 🙂 Yeah well it feels that way doesn't it?

If you really need it then you will just create a simple app where everything in your map is in your spatial reference.

You HAVE to have a basemap in ArcGIS Online (or Portal) because it defines the spatial reference for the whole map, so what I did was to make an empty vector tile layer and publish it, then tell the map viewer to use it as the basemap. Once you do that then you can add other layers in the same reference system and it should work fine.

[David_Brooks]

@IsobelMcLees is your web app in WGS84 geographic, or Web Mercator Auxiliary Sphere (the default SRS for arcgis online content)?

Vector tile layers need to honour the same cache/tiling schema as the basemap you have in the web map, which would be Web Mercator if it's a default esri basemap. The coordinate system of the map you publish from in Pro should also match this, but the underlying data can be in any coordinate system so long as youve applied the correct transformation in pro. (Note, arcgis enterprise doesn't support OSTN15 transformation out of the box, so you'll need to install it, or just use the #7 transformation from WGS84 to OSGB36)