Multiplayer Server for Steam Grayed Out

Our Steam user can't connect to our server now since the last patch. The line is grayed out. He can see the server but that's it. Any ideas?

run a steam integrity check on DCS

 

I remember something like this before but that was a few patches ago.

 

also make sure he is logged in to DCS when he starts

You do that through steam?

Is he missing any required mods, or possible he is not on the same version as you? I see a couple grayed out through Steam, and they all require a specific mod to be installed.

We don't use mods and the server integrity check is disabled. He was able to connect up to this last big update.

Thanks Bignewy, I'll ask him to check that out.

Thank you!