I am getting the error "The basemap you are adding has a different spatial reference from the current map." when trying to add a custom basemap (NOAA Nautical Charts) to the Basemap Gallery widget. I was able to add this basemap to an app in a previous version of the WAB and the basemap does still work. But when I edit that existing app, I get that same error.
Was there a bug introduced in the March update?