Hi! I use the ReportExecution2005 service to render reports and on the first rendering of the stylesheet, and on the first call to ToggleItem I get "A session identifier is required for this operation" exception. If I go back to the first "get" to my page and click ctrl+F5 it starts behaving well. Stylesheet and toggling works as expected. In my local environment, both on my computer and testserver (64bit) it works first time, but in my customers environment (64bit) it fails as described. I've checked that we've got exactly the same version of SQL Server. Any ideas where to start debugging? Lars-Erik

This was solved in cooperation with MS support. It was because we had set number of working processes to 2 on IIS 7. That made the user get two different sessions while rendering the report, giving the user two sets of session variables. L-ELars-Erik