groupadd: unable to lock group file

Hi guys,
i encountered this error when i try to create a group. What is the problem here? I created a few groups weeks before this. I was recommended to reboot the machine, but i am not the owner of the machine, thus i would prefer to know the cause and any other solution other than rebooting the machine.
Thanks in advance.

unlock group file - hope this helps - You didn't post what the OS and version of your server is.