How to Configure the ReportViewer in Sharepoint 2010
Follow The below Steps... 1. Navigate the c:\inetpub\wwwroot\VirtualDirectories\[Your port Number] 2. Make a backup copy of web.config 3. Open web.config in some text editor , may be notepad Look for following tag , ensure enableSessionState="true" 4. Look for tag and add below statement as last child node ( if not there already ) 5. Look for this tag below and update version to 10.0.0.0 6. Look for and comment the entry with name=ReportViewerMessages