I can not log in as a normal user, what is it?

Question

Debian

When I load the server, I can't log in as a regular user.
If I enter the login password of a regular user, then putty automatically turns off, I can only log in as root.
When the system boots, it says: Failed to start systemd Login Service

Answer 1

This is systemd. Log in as root and look:
Throw it here, but before that, find the line with the beginning of Main PID there and do:
and post it here too.