Configuring permissions can be tricky as there are many combinations and permission levels. With the Editor privilege level you just said that the user can get to the Admin UI. Then, for other actions you need to configure the permissions, in this case permissions for content module. Or, for particular page types. How are these permissions set in your case?
I would recommend using the security debug.
In browser A log in as admin and go to the debug section, load the security debug. In browser B log in as the user in question, go to the UI section you want. In browser A clear the debug log - so you will get the log only for the action you need. Switch to browser B and perform given action as the user. Go back to browser A and load the Security debug - here you will see what permission is denied or allowed so you can adjust them accordingly.