Error after a fresh installation of SSRS:
User domain\user does not have required permissions. Verify that sufficient permissions have been granted and Windows User Account Control (UAC) restrictions have been addressed.
1 Launch IE using “Run As Administrator”
2 Click on Site Settings > Security and add your user domain\user as a System Administrator
3 Click on “Home” and the Folder Settings. Add the user to all roles (Browser, Content Manager, My Reports, Publisher, Report Builder)