I believe this is game: 62088966 on oregon, penultimate turn.
I possessed the computer player. As I clicked the end button, I was notified of the game loss (as per usual, ahead of the animations for the computer player's turn).
The browser seems stuck at the clean-up phase (I can view cards, but cannot scroll the log).
After a Possession turn the log is messed up, which can affect things like undo. Doing a page reload (CTRL-R) usually clears that up. I suggest you try that and see if the game now properly ends.