Top Administrator - No access to Users

Hi,

All Top Administrators have the Users and User Group pages restricted with the message:
Page Not Found!
The page you are looking for could not be found! Please contact your administrator if the problem persists.

I tried to change the Top Administrator restrictions directly in the database but it didn't work.
I have even installed a fresh Opencart installation and copied over the whole oc_user_group table, but still... nothing works.

Getting very frustrated here.

Any ideas?

Many thanks

BTW, I do have access to the database via phpMyadmin and also to the backoffice, however, only the access to Users and User Groups in the admin are all blocked

Many thanks.

Any help please?