How login in after crash error?

Good day,
in file manager I try create .zip from public_html, he say red error: You must again log in.
Okay, but after F5 never can more login it, only loading Firefox or Chrome and no login page.
Whats the problem? 2 days can´t login in.

Check if the database is down.
Check available space in machine. df -h

If you run out of space, then go to the folder and delete that zip file.

Restart mysql

Not help, I have enough space.

The command “systemctl restart mariadb” not help, only loading and loading…

EDIT: Okay, I restart it hard from console and yet working.