Here what's happening when I try to log in.
I'm entering the right password
It brings me back me to the login screen.
I tried to change password via another user but it didn't help.
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If you've been starting graphic applications from the terminal using
sudo, that's what probably caused your problem. Always use
sudo mount -o remount,rw /# remount the disk as rw
cd /home/your_username# change directory
ls -al .*thority*# list some files
You should see something like this...
-rw------- 1 your_username your_username 407910 Nov 2 08:56 .ICEauthority -rw------- 1 your_username your_username 58 Jun 23 2017 .Xauthority
If it DOES NOT show
sudo chmod 600 .*thority*# change file protection
If it DOES SHOW
root root then...
sudo chown your_username:your_username .*thority* # change file ownership
reboot # reboot the computer
Reboot and see if you can log in.