I just upgraded my QlikView Server from v9 to v11. I foolishly thought that all that would be needed is to run the QV 11 installation files and it would automagically handle everything......quite apparently not.
I was running QV9 under IIS. I chose to install QV11 the same way....when prompted for a user, I apparently selected a different service user than what I had originally set up. After the install completed, I found that the QV access point page wouldn't load. I eventually discovered that I had to change the user on the Application Pool, then change the anonymous authentication user to my new user and the site loaded....well only sort of.