wine users - Aug 2011 - Interner Fehler: .NET Framework not found

Hello i have just tried to install the youtube Converter from DVDVideoSoft which
should work fine with wine following the WineHQ. After having made the prefix i
tried to install the program but then this error appears.
I have Mac version 10.6.8, the newest wine version and don't have any
knowledge about computers.

Thanks