[V7.511] Cannot bypass blocking URL

Hi,

We are still using V7.511 and want have users to be able to bypass the URL-blocking.
The help tells, that there is a field 'Users/Groups Allowed to Bypass Blocking' in
'Web Sercurity/ URL-Filtering', but this field is not present.
We only have the two fields: 'Additional URLs/sites to block' and 'Always allow these URLs/sites'.
I have seen the third field in V8.*** but not here.
The machines help-window, which is underlined with version 7.508 explains the bypass blocking, so it should be available in V7.511.

We are using 'Basic User Authentication'

Where can I switch this field on?

Thanks
Chris