Quote Originally Posted by caddis View Post
Solved!
I had to rename the file to Gmapsupp.img
Strange, all other maps have different long name files and they work perfectly

So the question is: why the file must be named Gmapsupp.img to be rocognized?
Are you sure the "other" file name had the file extension ".img"? If not, the map file is not recognised as a such.
Out of interest: try renaming the file again but leave the file extension intact. It should still work.