ExtensionManagerException

[Mark Wineman]

I've added the following code to my web.config file to disable certain export types and the rendering of column headers as rows in my Excel export:

<Telerik.Reporting>
    <Extensions>
      <Render>
        <Extension name="CSV">
          <Parameters>
            <Parameter name="NoStaticText" value="true"/>
          </Parameters>
        </Extension>
        <Extension name="IMAGE" visible="false" />
        <Extension name="MHTML" visible="false" />
        <Extension name="RTF" visible="false" />
        <Extension name="XPS" visible="false" />
      </Render>
    </Extensions>
  </Telerik.Reporting>

It works exactly as expected in my development environment (IIS 5.1), but when I deploy to our stagining/production (IIS 6) environment, I get the follwoing error when I load a page containing the Report Viewer.

TypeLoadException: A null or zero length string does not represent a valid Type.]
   System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) +7663440
   System.RuntimeType.PrivateGetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) +58
   System.Type.GetType(String typeName, Boolean throwOnError) +59
   Telerik.Reporting.Processing.ExtensionManagerBase.CreateExtensionInfo(String typeName, String extensionName) +45

[ExtensionManagerException: Error loading extension type with name .]
   Telerik.Reporting.Processing.ExtensionManagerBase.CreateExtensionInfo(String typeName, String extensionName) +83
   Telerik.Reporting.Processing.ExtensionManagerBase.Config(ExtensionInfoCollection extensions, ReportingConfigurationSection section) +285
   Telerik.Reporting.Processing.ExtensionManagerBase..ctor(IEnumerable`1 extensionTypeNames, ReportingConfigurationSection section) +95
   Telerik.Reporting.Processing.ExtensionManager.get_Instance() +96
   Telerik.Reporting.Processing.ExtensionManager.ListExtensions(Type extensionType) +11
   Telerik.Reporting.Processing.ReportProcessor.ListRenderingExtensions() +20
   Telerik.Reporting.Processing.ReportProcessor.GetRenderer(String name) +36
   Telerik.Reporting.Processing.ReportProcessor.RenderReport(String format, IReportDocument reportDocument, Hashtable deviceInfo, Hashtable renderingContext, CreateStream createStreamCallback) +206
   Telerik.ReportViewer.WebForms.ServerReport.Render(HttpResponse response, String format, Int32 pageIndex) +462
   Telerik.ReportViewer.WebForms.ReportPageOperation.PerformOperation(NameValueCollection urlQuery, HttpContext context) +119
   Telerik.ReportViewer.WebForms.HttpHandler.ProcessRequest(HttpContext context) +164
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

Does anyone know what might be causing this? If so, what's the solution?

[Mark Wineman]

Well, if anyone is interested, I managed to resolve the problem myself. Turns out, and I vaguely remembered coming across a post somewhere along the way, that if you are going to reference the XPS file format, that you need to deploy the Telerik.Reporting.XamlRendering.dll - which I was not. Simply removing the line <Extension name="XPS" visible="false" /> resolved my problem.

Along the same lines, if you happen to type the name of the export format incorrectly, that will throw the same error.

One would think that the ExtensionManager or whatever entity is responsible for parsing the web.config setting would be a bit more forgiving. Oh well... it's all good.

[Chris Lee]

Thanks for the update.  I was missing that dll also and this resolved the problem!

Cheers!

Chris

[James Strope]

Thanks for that!  I ran into the same thing.  That XPS tag was in one of the examples I found on this forum, but wasn't listed in the Export drop-down anyway, so adding a line to exclude it just caused problems.

[Phil]

Dittos on the fix.  I am setting up a new test server and had also missed the XPSRendering.dll and getting the same not-so-helpful errors returned.