New to SCO OpenServer 5

This is my first post so sorry if I don't make any sense this time round.

We have a SCO UNIX server that produced the following list of errors (among others) when doing backup with tar:
tar: dev/inet/tcp is not a file, symlink or directory
not dumped.
tar: dev/inet/udp is not a file, symlink or directory
not dumped.
tar: dev/inet/cfg is not a file, symlink or directory
not dumped.

Also about two weeks ago, users connecting to the server using remote terminals couldn't log in using the root password so the server had to be rebooted before it allowed root to log in again.

I have never used SCO Unix, or tried any administration on a Unix server before, so I have no idea what/where I need to check to start troubleshooting the server.

Please help...anyone...?

/dev is a special directory containing special files. You are not supposed to back it up. Exclude it from the backup list.

You have many users logging in remotely as root? NO! NO! NO!
Stop that immediately!

Every user should have their own username and password. The root password is either unknown or random and kept in a safe place for use in case of emergencies. Remote root login is absolutely prohibited! Any root actions a user must do are done using sudo, either by running the specific program with sudo or gaining a root shell via sudo.

"couldn't log in" means what?! The users were treated with an electric shock whenever they typed "root" as the username? Their fingers dropped off? The client machines rebooted spontaneously? They simply forgot the root password?