System.MissingMethodException: Method not Found: 'System.collections.specialized.NameValueCollection....

[InfoTrak]

We have a web application using reportviewer and on some client sites the application runs without any problems, but on some deployment sites we get an error and the only way for the page to load is remove one line of code (which then means they cannot view the report).

The full error returned is

System.MissingMethodException: Method not found: 'System.Collections.Specialized.NameValueCollection System.Web.HttpResponse.get_Headers()'. at Telerik.ReportViewer.WebForms.Utils.get_IsClassicPipelineMode() at Telerik.ReportViewer.WebForms.ReportViewer.CheckHttpHandlerRegistrations() at Telerik.ReportViewer.WebForms.ReportViewer.OnInit(EventArgs e) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
 
If I remove this line the page loads

 

<telerik:ReportViewer style="z-index:1000" ID="ReportViewer1" Width="990px" Height="1050px" runat="server" ShowDocumentMapButton="False" ShowHistoryButtons="False" ShowZoomSelect="True" Skin="WebBlue" Visible="false" BackColor="White" BorderColor="White" ForeColor="White"></telerik:ReportViewer>

Any help would be appreciated.
Thanks

 

 

[Steve]

Hi Monica,

This error can occur if you're running vanilla version of .NET 2.0. Please upgrade to .NET 2.0 SP2 or install a more recent version of the .NET framework and you should not have this problem.

All the best,
Steve
the Telerik team