Apologies for the post in English (your English is certainly better than mein Deutsch)
I have a Garimn Oregon 450 device and a MAC computer. I have downloaded the map of Switzerland. I converted the map using KaVawa converter and installed it onto my device. I can see the map in my device map list, but the map does not appear on the device screen (this maybe because I am in the USA, and the map is of Switzerland. I have had a similar issue with other European maps). More difficult, the map is not recognized by Garmin Basecamp. It does not appear on the basecamp map list, and I cannot see the map.
Any help or suggestion??