I'm on PC, Insanity difficulty.
During the final boss fight, I've had my game crash in a few different ways throughout the fight.
1. When the final boss spawns the second wave of Geth, the screen turns red/pinkish and locks up. Music continues playing, had to close via task manager.
2. Same as above, but the game instantly crashes to desktop instead of locking up.
3. Managed to finish the fight, but the game crashed in the cutscene afterwards (losing your progress).
editing for clarity:
SOLUTION:
the crashing is caused by biotic power usage, from both you and your squadmates. the only solution seems to be turning off auto ability usage for squad, and just gun him down. barrier seems to be okay, but offensive biotic abilities will lead to a crash either during the fight or the cutscene after (unless you're lucky.) my gut tells me the crash is caused by biotic abilities knocking enemies outside of the fight room, either ejecting them from the arena or causing them to get stuck in the wall.
protip: use high explosive ammo. it's rough on insanity with no abilities, but doable.
FYI the workaround here is to NOT USE ANY BIOTIC POWERS. I just managed to get through the fight (annoyingly) without biotic powers (you OR your squad members).
