When escaping from the labrynth beneath spellhold, you fight "Loonk" the mage, and have autosave enabled. If you kill the mage and then click to go down the stairs before the "free prisoners script" starts, you will be stuck in the game. You are not able to confront Irenicus. I have to go completely thru the labrynth when I found this. Waste of time, no way to fix it because no console on the ipad.