Support

 I cross reference this with someone else's ticket 22291 where I think they notice the same as me.
In the menu items for ATS, there are New Ticket, My Tickets, Latest Open, Categories, Assigned Tickets (at least that is as far as I have got so far).
I have an Administrator, a testuser (in Customer Service Access group) and a customer.
All these Menu Items open fine except Latest Open - this works for Administrator but 403s for testuser and customer.
I have my joomla expert (currently in Greek islands, lucky) check that I set permissions correct for Menu Items and Categories and he cannot see any differences between the settings for the different menu items.
I then read ticket 22291 and go to the Options in ATS, go to Permissions and grant Allowed to the Customer Service Access group for Access Administration Interface
Now Administrator AND testuser can see Latest Open, but Customer still can't.
If I understand 22291 correctly, this is desired behaviour and that Latest Open is only viewable to the Groups which have Access Administration Interface permission?
These are all Private tickets btw.

Thanks Nicholas, I had already set up Customer Service Access viewing level as per what your Quick Setup said for "Customer Support Access" .
It is most helpful to have my guesswork confirmed. Thanks and have a good weekend.