To get this resolved you need to start you Internet Explorer as Administrator -> Run as Administrator then open the url http://<Server name>/Reports this will take you to the "SQL Server Reporting Services" Home page

• Click on the "Folder Settings" button.
• Click on the "New Role Assignment" button.
• Add the Group or user name: DOMAIN\USER_NAME, and permissions you have logged in as.
• Click on Ok button.

This should resolve the issue.