Cannot use any menus in lobby

This is quite unusual! and doesn’t appear to be something widely reported. It’s a shot in the dark, but do you use any mods? If so, can you please try disabling them and see if the issue persists?

Otherwise, I it may also be a local issue with your installation.

You can try verfying integrity of game files:

1. Right-click Vermintide 2 in your Steam library sidebar
2. Select ‘Properties’
3. Select the ‘Local Files’ tab
4. Select the ‘Verify the Integrity of Game Files’ button
5. When complete, close and reopen Steam

Or, a clean reinstallation of Vermintide 2: