I have an Internal ONLY Map that is our Engineering Atlas. It works just fine. I recently upgraded my WAB. I just made some minor changes...
Removed a Widget.
Set the Map Extent to equal whatever was set on the AGOL side.
And that is all.
I downloaded from the WAB and uploaded to our internal server. I renamed the old map to "backup_NAME" and replaced the downloaded copy under the old NAME.
I'm getting a White Screen of death.
Here is my error message...
I made sure to update the proxy.config to point to the DotNet proxy that we have... but still... White Screen.
SO... I changed the URL for the updated on to OLDNAME+map so I can have them running side by side. Nothing I do makes the white screen go away.
Here is EngAtlas working fine:
Here is EngAtlasMap NOT working:
Same map, just from updated WAB.