Page Manager no longer functions properly. Installing it does not show a "Manage Pages" option or similar in the Configuration menu, and attempting to access ~/admin/index.php?module=config-pagemanager after installing the mod throws an Access Denied error.
check the admin permissions
admin panel >> users & groups >> Admin Permissions >> [edit permissions for your admin account]
--> configuration (tab) --> can manage pages ?
Geez. Why is it hidden all the way in there, and why is it user-specific? Ugh, but I digress. That needs to be mentioned on the mod's page.
^ if you have a number of admins then you can also add the permission to all administrators
admin panel >> users & groups >> Admin Permissions >> Group Permissions (tab) >>
Administrators --> configuration (tab) --> can manage pages ?
Ridiculous! Had the same problem, never thought it would be a permissions thing. This thread saved me from 40 minutes of heavy breathing and frustration, so thank you!