Cant display map data

The icon in the upper right of the map screen, where I used to be able to select the map data source is missing. It's been a while since I used the viewer. Perhaps they just moved it, but I can't seem to find it.


Start by reproducing the map screen and comparing its upper-right controls with the screenshot in the issue. Trace the current map-data-source control from the map screen; done means users can again find and select a map data source.

Written by the indexing model from the issue text.