Deleting a Group that has a Role in it creates an error

[QuinnBast]

Deleting a Group that has a role in it produces this error:

Once clicking OK, the group 'looks' like it still exists with the Role in the group:

However, clicking on a different group will cause the group to disappear and the Role to be placed in the list of Roles on the left.

[ShawnClake]

This is now fixed. The problem occurred because the session wasn't properly being reset when deleting a group. As well, added error checking for when no groups exist.