Concerning game #32906648 on frankfurt
My opponent wanted to undo a discard. The screen informed me he/she wanted to undo 83 items. Through discussion, we learned that he/she was hitting the undo button not using the command line. We played with it a bit, it always said 83 when he/she hit undo but not when I did. Screenshot of what I saw is attached.
Please not that it wants to undo -83 steps, so it actually wants to go 83 steps into the future. I'm pretty sure Possession being played is the culprit, the log gets decimated and this causes all kinds of problems.
In that case, hitting reload (CTRL-R) once you are again "yourself" should be the first action to do to avoid those bugs.