Suddenly cannot ssh with root anymore (requirement uid>= 1000'' not met by user)

[wmac]

Hello

My server was up and running and suddenly this is what happens. I try to SSH to root (using my trusted private key) and server disconnects and this is the error I see in the logs:

pam_succeed_if(sshd:auth): requirement uid >= 1000'' not met by user root

What has happened? What should I do?

[FreshLondon]

Try disabling SELinux and seeing if that helps:
https://linuxize.com/post/how-to-disable-selinux-on-centos-7/

[wmac]

Thank you very much for your help.

Strange thing... it resolved automatically after a reboot

The SElinux was already disabled.