Unplanned
Last Updated: 03 Dec 2021 12:59 by ADMIN

Repro: 

<telerik:RadStyleSheetManager runat="server"></telerik:RadStyleSheetManager>

<asp:UpdatePanel runat="server">
    <ContentTemplate>
        <asp:Button Text="Postback" OnClick="Unnamed_Click" runat="server" />
        <telerik:RadButton runat="server" Visible="false" ID="RadButton1" Text="Telerik button" AutoPostBack="true" />
    </ContentTemplate>
</asp:UpdatePanel>

protected void Unnamed_Click(object sender, EventArgs e)
{
    RadButton1.Visible = true;
}

<add key="Telerik.ScriptManager.EnableHandlerEncryption" value="true" />

 

Workaround:

Temporarily set EnableHandlerEncryption to false or do not use a StyleSheetManager

<add key="Telerik.ScriptManager.EnableHandlerEncryption" value="false" />

Won't Fix
Last Updated: 12 Oct 2015 11:49 by ADMIN
Instead of an exception the file should be served uncombined.

To avoid this, you can simply remove the StyleSheetReference entries from the StyleSheetManager if you do not intend to have them combined. Having them there will not bing a performance benefit if they are not combined.

The other option is to add the appropriate folders in the web.config:
<appSettings>
	  <add key="Telerik.Web.UI.StyleSheetFolders" value="~/folder1; ~/folder2" />