[Solved] The Telerik.Web.UI.WebResource.axd handler can return uncompressed content for browsers that accept gzip encoding and vice versa

[Telerik Admin]

PROBLEM

The Telerik.Web.UI.WebResource.axd handler can return uncompressed content for browsers that accept gzip encoding and vice versa

 

SOLUTION

Either upgrade your Telerik.Web.UI assembly to version 2009.3.1118 or higher.

Or, add this code to your Global.asax file:

C#

protected void Application_PostRequestHandlerExecute(object sender, EventArgs e)
    {
        HttpApplication app = (HttpApplication)sender;

        if (!app.Request.RawUrl.Contains("Telerik.Web.UI.WebResource.axd"))
            return;

        HttpCachePolicy cachePolicy = app.Response.Cache;
        cachePolicy.VaryByHeaders["User-Agent"] = true;
    }

VB.NET

Protected Sub Application_PostRequestHandlerExecute(sender As Object, e As EventArgs)
    Dim app As HttpApplication = DirectCast(sender, HttpApplication)

    If Not app.Request.RawUrl.Contains("Telerik.Web.UI.WebResource.axd") Then
        Return
    End If

    Dim cachePolicy As HttpCachePolicy = app.Response.Cache
    cachePolicy.VaryByHeaders("User-Agent") = True
End Sub

UPDATE (11/18/2009): The Accept-Encoding header has been removed from the VaryByHeaders property as this is preventing Internet Explorer 6 from caching the response.