I've had this problem on my laptop recently, too. I think I then started wwmp2wmb.exe directly from the GStudio folder, an error appeared and stated that one DLL was missing, d3dx9_30.dll or similar. So please start the map compiler, i.e. the executable, and check the error message.
"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual
