As you can launch in Modded realm this indicates the issue is Easy Anti-Cheat related. As this only applies to Official realm.
Are any specific error messages displayed on screen?
In any case, I recommend to try the following first -
Ensure you have appropriate Anti-Virus and Firewall exceptions in place for both Vermintide 2 and Easy Anti-Cheat.
You’ll need to add the following exceptions:
- vermintide2.exe in
\Program Files (x86)\Steam\steamapps\common\Warhammer Vermintide 2\binaries - vermintide2_dx12.exe in
\Program Files (x86)\Steam\steamapps\common\Warhammer Vermintide 2\binaries_dx12 - EasyAntiCheat.exe in
\Program Files (x86)\EasyAntiCheat
If the issue persists, next please try a ‘Selective Startup’ which can help determine if a background application is conflicting. To do this, please:
- 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 as normal, and see if the issue persists
If the issue no longer occurs, please try reintroducing your background applications one-by-one to identify the culprit.
Please let me know how this goes.