At my job, I have been tasked with fixing an error with our reporting server. That error is ASP.Net Session Has Expired. This error occurs when the Visual Studio ReportViewer 2005 Control attempts to load a report. We are trying to host this report to users hitting our Internet exposed Windows 2003 Server running IIS 6.0. The reportviewer control is attempting to load this report from a second server running Microsoft SQL 2005 w/Reporting Services. The SQL server is not exposed to the Internet.

Here is the weird thing. This error never occurs on the development box. When it is transferred to the production IIS server, the error starts to occur. It only happens every time the report is first loaded. If the browser's refresh button is clicked 5-10 times, the report will finally load correctly. I have reproduced this same error on the latest version of Mozilla Firefox, IE 7, and IE 8. The report only takes 10-20 seconds to load. I have tried timeouts in the 300+ second range on the reporting server/iis production server.

I have tried a few options like Async (which causes images not to load properly) and setting the session mode to iproc with a high timeout value in the Reporting Server's web.config. I have also tried using the reporting server's IP address in the report viewer's code instead of the server name. I plan on verifying a picture loading issue which I also read about tomorrow when I get into work.

I am unsure what service packs Visual Studio 2005 and the MSSQL server are running. Was an update released to fix this problem that I could not find? Does anyone have a fix for this?