When I try to open a page using the url '../p/PageName' without an active session in an application with a custom login page, I will be redirected to my custom login page. The result of this redirect is that I no longer have the link to the page I want to open, resulting in a 'normal' login. It seems that Mendix currently does not support using page url's in combination with custom login pages. It seems logical when offering the possibility of creating custom login pages, that this works in combination with other standard Mendix functionality.