I tried it but it don't work...

Registry branch: Computer\HKEY_CURRENT_USER\SOFTWARE\Policies\Micro soft\Office\16.0\Common
New value => DWord Entry "NoFontMRUList" => Value "1". After I restarted my PC and started Word and I see that all Font entries were in. Too bad that it won't work. I will continue to look for a solution!

Thanks anyway...
Mike