gnome-terminal will not load, sudo gnome-terminal will
I got this - it coincided with suddenly needing to enter a Keyring password on every login. I think that started after installing chrome-remote-desktop.
It also screwed my sound - no sound device:
The fix is here: Installing Google Chrome Remote Desktop messed up my box
All I had to do was sudo rm -rf ~/.config/chrome-remote-desktop and reboot.
I got my sound back and I could launch gnome-terminal again
chrome-remote-desktop was the culprit