showgroups error

[fundamentalsci]

When opening page View site leaders, Administrators who was hidden in admincp by the usergroup option "Viewable on Show Groups: No", the corresponding page did not change correctly and showed them about one day after change.
Now the following php headline error on this page occurs:
148315
What can explain the issue and how to correct the error?

[ozzy47]

Have you tried on a unmodified default style?
Have you tried with all mods disabled?
What vB version and PHP version are you running?

[Zachery]

The issue is because he doesn't have at least one usergroup set to show on the showgroups page.