AjaxManager not found…null
问题 I have a User Control and a Content Page . In the Content Page , I have a RadDockLayout control inside Update panel like below. I have an Image button , Once user swaps the position of RadDock by Drag Drop . User presses save button to save the order in database. <asp:updatepanel id="UpdatePanel1" runat="server"> <ContentTemplate> <telerik:RadDockLayout runat="server" OnLoadDockLayout="RadDockLayout1_LoadDockLayout" ID="RadDockLayout1" OnSaveDockLayout="RadDockLayout1_SaveDockLayout">