I finally upgraded from 1.1.3 to 1.2.2 and I'm having issues. Fresh, clean install of Ubuntu Gnome 16.04 and a newly extracted install of KSP 1.2.2. I've also tried with 1.2 with the same problem.
I start KSP and I get the loading screen and it does it's thing. However, once the main menu loads, KSP crashes and I get logged out of the OS. Not sure if it's the xserver that's restarting or what. I'm including the last bit of my ksp.log file. If there's a way to post the whole thing, let me know. This is the only part that I see that has anything that looks bad. Everything else looks like it's loading just fine.
[LOG 07:43:48.512] Loading Systems: Elapsed time is 70.94635s
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[WRN 07:43:50.135] The referenced script on this Behaviour (Game Object '<null>') is missing!
[LOG 07:43:55.830] [UIMasterController]: HideUI
[LOG 07:43:55.836] [Agent]: Found 19 agent mentality types