No Serializer avaiable error

hey guys,
since yesterday I get the following error:

Xenko.Core.Serialization.Contents.ContentManagerException: 'Unexpected exception while loading asset
[GameSettings]. Reason: No serializer available for type id f6e78a35184f6fe1d27096e38ec09340 and
base type Xenko.Data.Configuration. Check inner-exception for details.'

I dont know what I could have changed to cause this error. I have already read that maybe I have some missing dependencies like Xenko.Physics…silly question but where can I see which packages I need?

any other ideas?

Open the file in a text editor and see what types are referenced there.
Alternatively clear the cache and try opening the project again.