Prerequisite failure error when upgrading from StoreFront 2.6 to 3.0:
An error occurred during installation. Please ensure all the required prerequisites have been installed and run the installer again.
Looking into the c:\windows\temp\storefront\Citrix-DeliveryServicesRoleManager file, then searching for “exception” revealed that the upgrade is failing because of an error in the web.config file for the store.
One of the servers had upgraded successfully, so I pulled both the web.config files and compared the two: “BAD” server – logonmethod=”SSON” and “GOOD” server - logonmethod=”sson”I went ahead and changed the “BAD” server web.config file to logonMethod=”sson” (lowercase) and re-ran the upgrade.