This Fatal Scar Error usually occurs when you mess with the storyline of the game for example when you first kill St.Anais using the control enemy option and then you destroy the shrines.It happened on Dark Crusade for me as well using reclaim's trainer.It's the messing with the storyline that creates this error not the trainer specifically.
Same thing happened to me except it was on the Necron Stronghold. When I destroyed the Monolith before I was supposed to (because I used the Soul Drain power before the objective marker appeared), the game frozed up on me.
Lesson learned, don't f**k with the game scripted events or you'll be punished
[Edited by revan0123, 1/24/2013 2:47:56 PM]
[Edited by revan0123, 1/25/2013 5:20:43 PM]