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

In terminal, try this...

cd                              # change to home directory
ls -al .*auth*                  # list some important files

-rw------- 1 decker decker 405834 Oct 11 07:39 .ICEauthority
-rw------- 1 decker decker     58 Jun 23  2017 .Xauthority

The "decker" name might be slightly different, depending on your actual username.

If it shows anything other than rw, or different usernames, you'll need to either:

cd                               # change to home directory
sudo chmod 600 .*auth*           # set to rw
sudo chown decker:decker .*auth* # change the username if need be

Regarding the keyring, make sure that your actual login password is the same for the Default/Login keyring(s). Use the Password and Keys (18.04.1) app to change it.