Not on system console

Cause

A user tried to use the login(1) command to a system as the superuser (uid=0, which is not necessarily root) from a terminal other than the console.

Action

Log in to that system as a normal user, then run su(1M) to become superuser. To allow superuser logins from any terminal, comment out the CONSOLE line in /etc/default/login (this is not recommended for security reasons).