Reporting Services Error after Content database restoration

Question

I have migrated two web application content databases to from one SharePoint 2010 farm to another.

Reporting services seems to work fine on one of the web application.

http://webapp1/sites/intranet (All reports works fine over here)

http://webapp2:90/sites/intranet When I click on any datasource in a report library across the entire site collections on this web application, I get this following error

Report Server has encountered a SharePoint error. ---> Microsoft.ReportingServices.Diagnostics.Utilities.SharePointException: Report Server has encountered a SharePoint error. ---> System.NullReferenceException: Object reference not set to an instance of an object. ---> System.Exception: For more information about this error navigate to the report server on the local server machine, or enable remote errors

This looks to me as some problem with SharePoint or IIS and not with the Report Server. Can somebody help me out over here.

Answer 1

Finally found the actual cause after I closely followed this link: http://social.msdn.microsoft.com/Forums/en-US/sqlreportingservices/thread/daa59eec-b651-42dd-9f6c-42aaa3fa4523

Looks like the original account that was used to create the *.rdl files and the data connection library was removed from SharePoint.

The resolution is download the rdl files and delete the existing ones. Modify their datasources using Report Builder and upload them back through an existing user account in SharePoint site.