Rock is not in the sudoers file

Today I receive this message using sudo with whaever command:
rock is not in the sudoers file

Yestedar It was working fine. I dont’ know the cause of the problem but rock is not enabled today as sudoers.

How can I solve this stuff? I know I can edit the sudoers file in etc dir, but I have no enought permissions for it!

Thanks.

Does command sudo su work?

It doesn’t work. I receive the same error.