Hi, sorry if this issue has already been discussed elsewhere, but thought I would post this just to spread awareness. i love the black cat ring and always wear it basically and I just had a really bad interaction with Walt in the DLC. Basically when he betrays you it doesn't fully kill you due to the black cat ring, but it puts you into a state of not being able to do anything
Attached is a screenshot of what it looks like, but yeah, you can't even open a menu in this state so it is an Alt + f4 bug. Anyway, love the game just wanted to let folks know if its not already common knowledge :)