playmec

Looks like the forthcoming patch will address this issue (and MANY others): https://forums.obsidian.net/blog/7/entry-179-patch-notes-103/

I've had the same issue: early in the Endless Paths, middle of a Combat session, two characters stuck in place and won't fight, won't use Quick Slot items, etc. Pretty much the only thing they would do is change weapons and get thrashed by the enemies they should have been fighting. Not sure if this is related to another issue -- see http://forums.obsidian.net/topic/73144-bug-endless-combat-in-prison/?do=findComment&comment=1608622 -- but they did both happen in the same Combat session. I do love the game but it may be time to take a break for a while. Maybe after a few patches things will run a little smoother.

FWIW I've experienced this same bug a little deeper in the stronghold. After we talked to the Custodian -- whatever the talking statue up in the main hall is called -- we were able to get past the doorway just off the prison that was previously blocked by the force-field. In there, at the room with the Wyrm, Priests, Champion etc, we got stuck in endless combat too. The enemy were long dead but there was seemingly nothing we could do to get out of combat mode. I tried everything I could think of but eventually had to abort and quit out of the game to get out of Combat. I'm on Steam, Linux Mint 17.1.