This is a very odd/specific situation. I have an DNN 6.2.3 installation and it works fine when local users access it.
When user VPN into our system, they go through a Citrix web proxy and this causes an issue.
They get to the login page, type their username/password and click Submit.
The page flashes, but just stays at the login page. It does not redirect to the HomePage.
But, if they click one of the links on the top menu, it lets them in as if they had been authenticated.
My thought is some resource the login page was trying to access was getting blocked by Citrix,
but there are no external links on the HomePage.
I had the Citrix admin add the Google Ajax Api URLs to the allowed list. I don't see ANY messages in the Event Viewer, so I'm not sure where else I can check.
Anyone have any ideas of what else I can try?