Cannot log in (guest or not)
Today I edited some audio with audacity. But it was taking too much time so I powered off my machine, abruptly, by holding the power button.
Upon restart, I cannot log in or do anything useful with my computer.
I have three options when logging in in terms of desktop environment: MATE, i3 and i3 debug mode.
I have tried both entering the password for my user and using a guest session with the 3 desktop environments mentioned above and the result is the same always: the same screen of user authentication is provided.
What can I do?
Is there a problem because I didn't log out appropriately before? Is there an open session?
How could I reinstall the OS maintaining all the files?
"I powered off my machine, abruptly, by holding the power button."
That's not a good idea.
"Is there an open session?"
Probably more like corrupted files.
"What can I do?"
Maybe try not doing that in the future. :)
Hopefully you have a backup.
You can try to repair the filesystem mounted at /home from a live system (for instance Trisquel's installation medium), without actually mounting it. If that filesystem is /dev/sdaX (where "X" is a number and "a" may actually be another letter if /home is not on the first disk) and is of type XFS (Trisquel's default), you can try:
$ sudo xfs_repair /dev/sdaX
If that is not enough:
$ sudo xfs_repair -L /dev/sdaX
Thank you comrades for your help.
I solved the problem doing the following.
In the screen that I am stuck (log in screen) I invoke a terminal (C+M+F2).
Then I do apt-get clean, autoclean, check, update, and everything else that seems to purify my system.
Then I reboot and everything is perfect.
Brilliant move! Sometimes the best ideas are right there in front of you.