Hi @fangzan,
Sorry to hear this. The error is certainly EAC-related!
Please can you try repairing EAC:
- Navigate to: C:\Program Files\Steam\steamapps\common\Warhammer Vermintide 2\installers\EasyAntiCheat
- Run the EasyAntiCheat_Setup installer and proceed as instructed
Please let me know how this goes.