InsertExternalVideo not working

[Skúli]

Hello,
I have InsertExternalVideo in RadEditor. All of a sudden it stopped working. Now i get the error you see in the attachment.
Here is the code:

<telerik:RadEditor ID="RadEditor1" Runat="server" EditModes="Design" ExternalDialogsPath="~/Telerik/EditorDialogs/">
        <Tools>
        <telerik:EditorToolGroup>
        <telerik:EditorTool Name="Bold" />
        <telerik:EditorTool Name="Italic" />
        <telerik:EditorTool Name="Underline" />
        <telerik:EditorTool Name="Undo" />
        <telerik:EditorTool Name="Redo" />
        <telerik:EditorTool Name="InsertExternalVideo" Text="YouTube" />
        </telerik:EditorToolGroup>
        </Tools>
        </telerik:RadEditor>

The file ~/Telerik/EditorDialogs is there. This happens both on my local and remote server.
This worked before and I did not do any changes to the file. Do you know why this is?

[Rumen]

Hello,

Have you upgraded the Telerik.Web.UI.dll to a newer version? If so, you should also update the files in the EditorDialogs folder and modify them from scratch. The EditorDialogs folder and the Telerik.Web.UI.dll should be always taken from the same RadControls for ASP.NET AJAX installation, because the codebehind files of the RadEditor's dialogs are embedded in the Telerik.Web.UI.dll.

If your scenario is other, isolate the issue in a simple working project and send it for examination.

Kind regards,
Rumen
the Telerik team