Was playing Shipyard and hacking the last objective when I got thrown back to the Serverbrowser. No error message or anything.
Search and Join buttons were greyed out. Happened before so I just restarted the game. I did not Alt+Tab today.
After restarting I was asked which side to join and I created a random character to find my four lvl 20s gone.
Had one of each class and it doesn't seem to be the known bug.
Only thing altered were the start options, added novid and VOIP soundlevel 0

I can live with many bugs even if they're very annoying but this is one who breaks a game imho.

Damn level 20s all four, I never seem to be able to make it past level 15 without deleting my people.

Just make another its fun creating character make a multi class character for something different.