przemratajczak/mangos — comment on commit 307ea60615f5c83a428abd9b4cabc1527c016f8f
File: src/game/Object.cpp line 1193
By Schmoozerd:

Yes - I got a bunch of these crashes as well.
In my cases they all were caused by
bad auras in creature[_template]_addon
or in one case a bad spell in EventAI

these spells set the npc into combat with themselves and hence crashed here..
Actually I have no idea, why they did not crash before (atan2(0, 0) should have been crashing..)

If you don't get reasonable crash-logs, then maybe use DBError output with GetEntry() to be able to track them down