Same problem here. Has been working fine for weeks. No changes we know of and suddenly users of the child portal lose their logged in status when navigating away from the page they were on when logging in.
We upgraded to 4.9 but that had no effect on the problem.
Parent portal and other child sites are working fine. This has happened before long ago with another child portal on another installation but we were able to delete the portal and recreate a new one, so never tracked down the problem. This is not an option now - we need to find the cause to restore client confidence in the software, and fast.
Server, Site, and User time zones all appear to be the same. Host accounts can login fine, only child portal users, included the Admin, lose their logged in status after a successful login (Event Log records a successful login, and Members Online module shows them as logged in).
Happens across multiple computers, across browsers (IE Firefox Opera Avant Chrome), tried clearing cookies, so it isn't a client issue.
Deleted and recreated a user and role, still won't stay logged in.
Tried a different skin file (DNN Default), same problem.
Any ideas on how to trace what is happening when loading a page and following how DNN checks for permissions to find out what is failing?
Thanks! All suggestions are welcome.