[2022] Server Error : Backend rejected the challenge response

It sounds like Easy Anti-Cheat is placing you in to an “untrusted” state, which mimics the errors we would expect to see in the ‘Modded’ realm. I suspect something is interfering with Easy Anti-Cheat, could you try a ‘Selective Startup’?:

1. Press the Windows key
2. Type ‘msconfig’ and select ‘System Configuration’
3. On the ‘General’ tab, select ‘Selective Startup’
4. Deselect ‘Load startup Items’
5. Reboot your PC
6. Launch Vermintide 2 as normal and see if the issue reoccurs