This might also be a card bug, but the more I think about it the more I doubt it.
Game #5170 on frankfurt-test2
Turn 16: the AI repeatedly discards to my Vaults leaving it with no cards in hand. When I play a Vault and it has no cards in hand, it goes into endless wait for the AI to do something.
This seems like it is the AI refusing to take the no discard option and so becoming stuck - I don't know that this situation would ever arise with a human player but forcing no discard seems appropriate.