IIS backward compatibility components were not detected (Upgrade Advisor)
Upgrade Advisor did not detect IIS components and settings that provide information used by Setup to create new Reporting Services URLS.
Applies to: Reporting Services Native mode.
After upgrade finishes, use the Reporting Services Configuration tool to set the URLs for report server or Report Manager. Use IIS Manager to remove the virtual directories you no longer need.
For more information, see Configure a URL (SSRS Configuration Manager) in SQL Server Books Online.