Advanced editors group cannot access pages
The Advanced editors BE User Group cannot see or access pages in the backend. The pages are all under "Admin" ownership. When the group were made "Owners" in System|Access, they were then able to see the pages to edit. Is that the best way to configure the example Advanced Editor BE User?
Most probably advanced editors where not defined in the permissions module - in TYPO3 v10 it can be found in the backend at System > Access.
Nice... advanced editors and simple editors are independent user groups, but inherit from all user group. Even in current configuration of the introduction package it is wrong → pages would grant access to all group, currently it's simple editors.