Groups view produces traceback instead of a forbidden page

We have two groups of security settings:

* List of accounts
* List of groups

Both allow the non-admin users to see that content.

By default if a non-admin users tries to load /persons, he gets a "You are not allowed to access this page" message and the login form. However, if the non-admin user tries to load /groups, he gets a traceback instead.

If the "The list of groups in the system is visible to the general public." setting is selected, /groups works as expected for non-admin users.