Please see the pinned post: About the Vermintide 2 - Technical Support Category to see what information to include in your report.
I recently downloaded Vermintide 2 and after startup I receive the error “Backend rejected the challenge response.” I’ve attempted to trouble shoot this myself doing the following:
Made sure I was on the Official server
Validated the game files via steam
Reinstall/repair easy anti-cheat
Do a clean install of steam and Vermintide 2
Disabled any Firewalls that may be interfering
At this point I’m unsure what to try next. Any help would be appreciated.
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’?:
Press the Windows key
Type ‘msconfig’ and select ‘System Configuration’
On the ‘General’ tab, select ‘Selective Startup’
Deselect ‘Load startup Items’
Reboot your PC
Launch Vermintide 2 as normal and see if the issue reoccurs