Playing the Death Zone scenario: third one in the Scenario 6, the one with the Ice zones.
Lem is fighting a Leng Spider. I intially considered using Summon Monster against the thing, but changed my mind and used her Bardic Performance to discard the Summon Monster instead.
It bugged out, I won the fight through Diplomacy, but then would summon a Mercenary to fight the Leng. Then Win or Lose the fight would stall and I couldn't do anything to the game.
Shut it down, restarted, it reloaded at the state of me ready to roll my combat dice with the Summon Monster being recharged. Same thing, Summoned a Mercenary then locked up.
I could not advance past this fight, and had to Forfeit the run. After the Forfeit screen my Paladin was holding the Summon Monster Card, not Lem, and they weren't even in the same zone.