I get to the part where you have to face down Singh's minions in the Lab. But mid fight the game crashes. I then load it back up and the two minions are just standing in their start locations and are non hostile, so I can't kill them.
So I abort the mission and try to go back in. Still non hostile. Then I abort, drop the mission, and restart from Korvat.
Then when I get to the same part the game crashes during the fight with Singh's minions and they are non hostile on reload. The game just doesn't want me to finish this mission it seems.