Steam family sharing bug

I'm trying to activate a copy of a game which previously has been shared with me by a friend of mine. I get an error that i already own the game followed by this screen. After that a message telling me the game can not be installed pops up. I've asked my friend to revoke access to his library thinking this will fix the problem but no - i still get the damn error.

I've followed this potential fix , but it didn't work either. Is anyone familiar with this issue and have you found a solution to it?
Help will be much appreciated.

PS: I already contacted support about this case but as you probably know - they're major slowpokes.