The resize handle of the Editor is not visible if only only edit mode is active (e.g. Design mode).
Steps to reproduce:
1. Run an Editor with the following configuration:
<telerik:RadEditor ID="RadEditor1" runat="server" EditModes="Design" ></telerik:RadEditor>
Result: The whole module row is not visible, including the resize handle.
Set the RenderMode to Lightweight and the resize handler will appear.