It seems like “the best oil” buff trigger is causing the crash.
Played two games in Void Thrashing as level 1 Stetmann with the “oil baron” prestige, and got fatal error in both games at first void thrasher.
First game crashed when a group of mecha zerglings were about to kill a marauder, and second game crashed when mecha zerglings were about to kill the void thrasher.