The XFCE graphical environment does not start when the user is authorized: what could be the reason?

Question

linux

MX Linux 19.4 patito feo
Problem: The XFCE graphical environment does not start when a user (user, not root) is authenticated. When authorizing with root, this problem does not exist. At the same time, user authorization in text mode (text interface Ctrl + Alt + F1) is successful, and I can work with my working directory.
Before this problem appeared, I deleted several files, updated the system and possibly drivers (I don’t remember exactly, but Synaptic, the driver manager opened for sure), and also performed a memory test.
My actions: cleared cash and restored deleted files in root mode, reinstalled lightdm: I hoped to get off with a slight fright. But, alas! the problem is not solved.
I also made sure that I have no possible causes of this problem:
https://mxlinux.org/wiki/system/cant-log-in/
Running the lightdm script (sudo lightdm as user) ends with a warning:

Faled to use bus name org.freedesktop.DisplayManager, do you have appropriate permissions?

The launch of the startx script is accompanied either by a fatal server error ( no screens found(EE) ), or it ends with a “slowed down” appearance of the working environment for the root user and a window on the desktop with the inscription No Removable Device.
In terms of symptoms, my problem is similar to this one:
https://forum.mxlinux.org/viewtopic.php?t=49960
Inspired by its solution, I created a file called nvidea in the ~/.config/autostart/ directory (based on the kbd.desktop file ) with stuffing as in post #10 of the above article.
As expected, it didn't help.
Please help/advice in solving this problem. Of course, as a last resort, you can reinstall the system, but this is not desirable for me, since the working directory has a lot of changed configuration (and not only) files that I have been adjusting "for myself" for several months.

Answer 1

Well, first of all, lightdm has to start as root, as a service, so no wonder do you have appropriate permissions?
You can try removing /etc/xorg.conf (or /etc/X11/xorg.conf) if it exists. If not, on the contrary, run X -configureto create a default config.
And carefully look at the errors above the no screen found line - this is just a consequence, the reason should be higher

Answer 2

Read logs: /var/log/Xorg.0.log , ~/.xsession-errors , ~/.xfce4-session.verbose-log