[2021] Vermintide 2 displays this message launching the game from the launcher game launcher, which is launched through steam. I was able to play the game last week, so something must have changed between now and then.

This one is on our radar, but we suspect right now at least the ball isn't in our court.

We'll update all we hear and know in our dedicated known issues page on the support site:

https://support.fatshark.se/hc/en-us/articles/4408080360337-Known-Issues