the page in AdvancedCMS cannot be shown because of a permission failure while you can see that all customer groups are set correctly
this may due to a bug in Prestashop where not all customer groups are displayed.
you need to go to every customer groups settings under Clients->Groups and re-save every of them. Than go to the page settings in AdvanvcedCMS again, check all customer groups and resave the page. It should work than