After entering the password - black screen (ubuntu 18). How to turn on the screen or system restore?

Question

linux

Played with gnome. Wanted to put a theme. Installed the initial package that allows you to install custom themes. In fact, he did not put anything. Then I decided to change the screen resolution. I tried different ones - I set 1600x900 in my opinion. It became a dull black screen. I waited a little. Look - he hung. Turned off the computer. Now after logging in with a password, the screen goes black. And that's it, it doesn't work ...
I tried to enter different commands. And I updated the system and did dconf reset. Nothing works. What to do???

Answer 1

Alt+ctrl+f2
A terminal will appear, log into your user there and restart your window manager, in ubuntu 18 the default is gnome+lightdm, here is the link for gnome
. Also check and change the permission https://askubuntu.com/questions/455301/how-to-rest... and LDM is restarted with the command sudo service lightdm restart
If nothing works, then delete via apt purge and install again, not forgetting delete or rename the .gnome and .gnome2 directories to /home/ or put another one, for example unity
Don't know which manager? Just install and run another one. Everything is googling on the internet.

Answer 2

Similar garbage in linux mint, when you enter a password, the screen fades, then turns on and asks for a
password again .