An error has occurred during report processing. (rsProcessingAborted)

Hi,

I am using SQL 2012 Reporting Services SharePoint Mode for SharePoint 2013 where I am hosting SSRS reports in SharePoint and they are pointing to SQL Server database which is local.  When I run the report in the SharePoint web page I get the following error.  Can anyone help me with this issue?  Any advice would be much appreciated.  Thanks! 

• An error has occurred during report processing. (rsProcessingAborted)
  • Cannot impersonate user for data source 'DataSource1'. (rsErrorImpersonatingUser)
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