In some cases at the borders of maps - there appear grey rectangles in Basecamp and Mapsource (well do not mind Mapsource much - it's very outdated) - this only appears if using a DEM/contourline overview...

Sorry as Basecamp is windows only - only windows installer/Mac OSX gmap file here:

https://openmtbmap.org/mtbbayern.exe

or 

https://openmtbmap.org/mtbbayern_macosx.7z

Without contourlines the map works fine (mapsetx.tdb...)

Contourlines map alone also does not work (mapsetz.tdb...)

So the bug is clearly in the transparent DEM/contourlines map. Sometimes simply rendering the contourlines map again and the bug is gone...

Seems to be not that common but also not that rare (maybe in 1 out of 20 maps)

--

Felix Hartman - Openmtbmap.org & VeloMap.org

Schusterbergweg 32/8

6020 Innsbruck

Austria - Österreich