I have tried running the GUI and it closed unexpectedly and without any error message. I thought it was an issue with the power controls, so I have turned off all power controls so the computer does not hibernate, or even turn off the screen.
As @nc50lc said, without any log/error message we only can guess or list all possible problems. Aside from
debug.log, please check your
journalctl and see any relevant message (such as I/O error, OOM killer is triggered or other hardware error). Usually i would this parameter,
sudo journalctl -p 3 -x -b -0
Where
-p 3 show error message (use
-p 4 to also see warning message),
-x is extra message and
-b -0 to show log from current boot.