When two RadEditors with different TrackChanges mode are defined on the page, a JavaScript error is thrown when inserting a list. The issue is reproducible only when the firstly declared RadEditor has EnabledTrackChanges set to false (the default value), while the second one has EnabledTrackChanges set to false. Temporary workarounds: Variant 1: Declare the not tracked RadEditors after the tracked ones, so there scripts will be loaded properly. Variant2: Set the EnabledTrackChanges of all RadEditors on the page to true. Steps to reproduce 1. Run the following code: <telerik:RadEditor ID="RadEditor1" runat="server"> </telerik:RadEditor> <telerik:RadEditor ID="HiddenRadEditor" runat="server" EnableTrackChanges="true"> </telerik:RadEditor> 2. Write something and press Enter 3. Click on the "Unordered List" tool Result: A JavaScript error is thrown