I tried that and it did not work.

My issue started to happen when I added a value in Tablix (Page Name), so that when I export the report as an EXCEL file each tab will have a specific name. It works fine when I run the report as a standalone report. It all fails when I try to open the rdl file when it resides in SharePoint 2010.

Here are my error messages;

The report definition is not valid. Details: The report definition has an invalid target namespace 'http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition' which cannot be upgraded. (rsInvalidReportDefinition)

System.Web.Services.Protocols.SoapException: The report definition is not valid. Details: The report definition has an invalid target namespace 'http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition' which cannot be upgraded.

at Microsoft.ReportingServices.WebServer.ReportingService2005Impl.GetItemDataSources(String Item, DataSource[]& DataSources)

at Microsoft.ReportingServices.WebServer.ReportingService2006.GetItemDataSources(String Item, DataSource[]& DataSources)

Troubleshoot issues with Microsoft SharePoint Foundation.

Correlation ID: 34f97b8b-a52c-4493-a6cb-3a1755db3dff

Date and Time: 12/31/2012 5:19:59 AM