I tried everything and couldn't get rid of the invincibility bug.
As soon as the Chaos Knight fight starts the Knight becomes invincible. I tried drinking the Power Potion before the fight, not taking the potion, not picking up the Knight's light armor, playing around with compatibility settings and different renderers.
Sadly, they didn't help me at all. The Knight's level is unplayable for me.
Post edited June 11, 2013 by Tuhnis