Recently we updated our ReportViewer library from the Visual Studio 2008 version to 2010. With the new version, the previously working wait control shown below was no longer rendering.
For the most part, the report viewer requires little configuration, but there are a couple properties that affect the display of this control.
Because the 2010 version is AJAX-enabled, you’ll need a script manager control on your page with the EnablePartialRendering property set to True. This is the default value. (Mine was previously set to False, which was the issue in this case.)
In the report viewer control, set the AsyncRendering property to True. This is the default value. The WaitControlDisplayAfter property is a red herring; it’s only used for subsequent postbacks, not during the initial laoding of the report.