RDL Reports are not working after installing SQL Server 2012 Service Pack 2 in the SharePoint integration Mode

Question

I am using Reporting Service Integration mode with SharePoint. SSRS is installed on separated machine of SharePoint stacks in Integration Mode. Everything was working properly and I could create/edit/modify RDL reports(parameters, Datasource, Subscription)
inside SharePoint and Document Libraries.
But after installing SQL Server 2012 Service Pack 2, on opening RDL reports inside SharePoint I receive this error message. 
The permissions granted to user 'i:0#.f|membership|username' are insufficient for performing this operation. ---> Microsoft.ReportingServices.Diagnostics.Utilities.AccessDeniedException: The permissions granted to user 'i:0#.f|membership|username' are insufficient for performing this operation
I should mention that SSRS is installed in the SharePoint integration Mode and there is no SSRS management console.

Answer 1

Hi Hedayat-Abedijoo,
According to your description, you are using Reporting Services in SharePoint Integrated mode, and everything worked fine before you install SQL Server 2012 Service Pack 2. After the package is installed, when you open RDL reports, the error occurred: The
permissions granted to user 'i:0#.f|membership|username' are insufficient for performing this operation.
According to my search, there may be two reasons for the problem:
This is caused when the application pool account that runs the SharePoint Web application you are on in IIS and the application pool account that SharePoint believes is running the site differ. This happens if the application pool account is changed directly
in IIS instead of through SharePoint (using the approved method).
This error can be caused when Kerberos authentication has been set up correctly and delegation in a double hop scenario will succeed, but Reporting Services integration has been set up for Trusted Account rather than Windows Authentication. This causes
SharePoint to continue to impersonate the logged-on user when contacting Reporting Services; when Reporting Services compares the application pool account to the user account making the request, they are not equal.
In this case, we can solve the problem by changing the application pool account in IIS back to the previous account and set AuthenticationTypes to RSWindowsNTLM only. For detail information, please refer to 8.3 “The permissions granted to user 'Domain\User'
are insufficient for performing this operation” in the document:http://msdn.microsoft.com/en-us/library/ee384252(SQL.100).aspx
If you have any questions, please feel free to let me know.
Thanks,
Wendy Fu