Simulacrum Game Crash

Always getting a freeze and then Crash when i start a round and a certain mob spawns and starts attacking with a red looking skill. Currently tested out by me and 2 Guildis and we all crashed together at the same time and individually.

We all tried stuff like clearing cache and other Stuff.
I reinstalled the Game twice.

But nothing changed.

Also i can run anything else except Simulacrum/Delirium if same Mob spawn.
Sadly i cant tell which Mob it is cuz Classic Deli Visual Clarity.

There some Rounds where we didnt crash at all so we are guessing it is a Certain Mob/Buff/Skill thats crashing the Game.

Quick Edit: The Game crashed once after the Black and White Orb Slam came from Deli