We are working on the Mac Client issue this morning and investigating reports of Window server crashes.
A few notes.
If you are trying a campaign in any gamemode and having issues connecting to a dedicated server, try to play locally. If it works locally, contact your server operator and ask them to update.
We will be removing all of the community campaigns we host on our servers and refresh them with the versions on the Workshop as they become available.
DO NOT UPLOAD CONTENT TO THE WORKSHOP THAT IS NOT YOURS!
If you do, the content will be removed and you will get a temporary community ban.
Please use the reporting tool to report any upload violating the Steam Terms of Service. You do not need to report how much that mod kicks ass.