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The styles of the ASP.NET Report Viewer's toolbar are messed up.


Product Progress® Telerik® Reporting
Report Viewer Legacy ASP.NET Report Viewer


The Legacy ASP.NET Report Viewer's styles are messed up on loading the report viewer in the browser.

web viewer toolbar

Possible Cause

This usually indicates that the ReportViewer control has not been able to load its stylesheet.


  • When the application is hosted on IIS7, i.e. the handler should look like the following:
       <add name="Telerik.ReportViewer.axd_*" path="Telerik.ReportViewer.axd" verb="*" type="Telerik.ReportViewer.WebForms.HttpHandler, Telerik.ReportViewer.WebForms, Version=x.x.x.x, Culture=neutral, PublicKeyToken=a9d7983dfcc261be" preCondition="integratedMode"   />   
    <validation validateIntegratedModeConfiguration="false" />     

Substitute Version=X.X.X.X with the exact assembly version you are using!

  • Check for runat="server" attribute in the web page's head tag;

  • Use a web debugging proxy (e.g. Fiddler Jam) to see what is the response for the /ReportViewer.axd?name=Resources.ReportViewerInternal.css&version=x.x.x.x&optype=Resource request or any request of such kind;

  • If you have global styles or themes applied on the page - disable them temporary to verify if they are the culprit. If this proves to be the case, make sure that styles/themes do not affect HTML elements directly, but are applied through the CssClass property.

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