Alright, so I downgraded the ps client to an older version that I had on my other computer. First I tried to copy/paste the backup folder like before, but that only gave me the same error as I previously encountered, so instead I replaced the whole installation folder. I launched the old version of ps, but when I ran sharky and pressed start I now got a window that Said:
Error
Could not synchronize Pokerstars Client, try again or contat support...
I thought that this version of ps probably was to old, so I copied the content of the backup folder that I used yesterday and pasted it into the downgraded pokerstars installation folder. Now a very buggy version of pokerstars launched. It looked like this:
I obviously don't really know what I'm doing and I think that the only way I can get this to work is if I can get a hold of someone else's installation folder. So if someone is feeling especially kind today and would like to upload their downgraded pokerstars.eu installation folder and pm me the link, I would be very happy