Thanks JD, 

Thanks for your suggestion. It's strange that I haven't touched anything on permissions or groups lately/past 2-3 months/ it happened just like that. And more interestingly when I checked the groups today to add the suggested most of what I added before was gone, so maybe that was it. I will inspect for a few days and report back whether it was solved by that.

On Thursday, September 10, 2015 at 12:51:41 AM UTC+3, JD Robinson wrote:
If you're getting booted off the system and out of the desktop environment, then you're violating some permissions somewhere or the service holding up your session is erring out on account of this.