Since Thieves Guild release, if I am logged into the game for more than 2 or 3 hours , when I QUIT, the screen freezes.
[I’m not sure of the threshold time, but it never happens in short sessions, always in 4+ hour sessions.]
I play in Windowed Fullscreen mode so I have to power off the iMac. Unless before quitting I switch to Windowed, in which case I can Cmd-TAB to the Finder and Force Quit.
Still happening with DB. iMac 27” 5K (late 2015)
[Note on game stability on my Mac: Since TG I have had about 6 crashes in-game. Each seemed different and random, not related to a wayshrine or transit. That’s about 1 crash every 75 hours]