Game crash for everyone in coop.

It's hard to tell exact reason of crash, but when I cast spark inside mana tempest and flame wall with archmage turned on, it sometimes crashes my game and even friend's of mine in coop. It's not happening every single time, but after few casts it does.
Crash occurs both in single player and coop.

UPD: It appears game crashes when I'm taking damage while casting this. I have Chaos Inoculation, Mind Over Matter and Eldritch Battery talents and Ghostwrithe chest (with this I still have energy shield for some reason), probably there's some bug in calculations that causes game crash in coop.