Playing circle of eight for the first time and got a gamebreaking problem just in the moathouse. After killing Lareth, any save I make is instantly corrupted. I can't progress at all. Any fixes/walkarounds to this?
Just curious, but have you tried to exit the moathouse, go to Hommlett, Rest and THEN go back and fight Lareth? maybe by leaving the area you will be able to save and continue the game.
Make sure you dont have any spell effect on yourself or on area. Sleep after fight to get rid off some long duration ones. During fight with Lareth, when he appears, make sure he goes through his whole dialog. In fact, dont attack him when he talks, just wait till he ends. If your druid pet get knocked out (disabled/dying), but was healed up and is alive, its better to dismiss it.