The aforementioned error may come up in several different circumstances:
– Deploying / Running your Report Project From Visual Studio or Report Designer
– Browsing to your Report Server URL http://servername/ReportServer
– Browsing to your Report Manager URL http://servername/Reports
In each case, the solution may be one, or a combination, of the following:
– Especially If you are running SSRS on a development non-server platform, make sure you have turned off UAC (User Account Control) on the OS Login (Control Panel>User Accounts And Family Safety>User Accounts>User Account Control Settings). The slider should be dropped to the bottom-most setting.
– Using your web browser, browse to http://servername/reports, click the properties tab (SSRS 2008) or click the SITE SETTINGS link in upper right (SSRS 2012), click SECURITY, select NEW ROLE ASSIGNMENT (toolbar button SSRS 2012), enter DOMAIN\USERNAME or DOMAIN\USERGROUP and check ‘Report Builder’, ‘Browser’, ‘Content Manager’, ‘My Reports’, ‘Publisher’, ‘System User’ and/or ‘System Administrator’ roles as appropriate for your situation.
– Add the [Domain\User] to Administrator and SQLReportingUser groups by right-clicking on COMPUTER and selecting MANAGE, then go to local users/groups and either select the aforementioned groups and ADD the user, or select the user and ADD the groups.