Useradd not creating users and just got blinking cursor

Suddenly useradd command is not working,no errors displayed and just got blinking cursor after hitting the command but not actually creating users as expected. Tried using the groupadd command but same results.

The last thing that I did if I can remember is changing the default run level from 5 to 3.

Example: 
root@station1 ~]# useradd Kerry

Any inputs will be highly appreciated.

Regards,
Norbie

I assume you went from 5 to 3 because the box is a server, not a standalone desktop.
Since you do not recall what was done it can be hard to pin down your problem. It could have started earlier but was not noticed until a lot later.

Try a full shutdown, power off. Boot to runlevel 5. This should NOT affect useradd. Check it anyway.

If you use sudo and made changes to /etc/sudoers I would look there first - stay with runlevel 5. When you edit sudoers you need to be aware of file format constraints, as in you cannot use an editor like gedit. Use visudo. That should be a given.

Please get back to us with questions. I hesitate to suggest drastic steps like a full restore from backup, or rebuilding the system from the distribution media with so very little to go on.

What is the OS system and version and what shell are you using?

Is there a directory service configured in /etc/nsswitch.conf for passwd/group?