Ah, like that. In which install(s) is that? Is the frame visible where the map should be or is there just the briefing frame?
I don't know how that map picture is generated. If it is a .bmp or .jpg, I can only think that it might be missing from that particular install. If it is somehow generated based on the theatre itself (the landclass stuff etc. that you are working on), there must somehow be a controlling file, like a .xml. Have you altered anything in those installs while working on new theatres?