Ajax html editor an issue with VS 2013

Ajax html editor issue with VS 2013 and calendar extender is coming from Ajax but getting an issue with the Ajax html editor not showing even design mode.

Ajax html editor showing in the design mode message like:

HtmlEditorExtender - Unnamed1

Below are my web config details:

<pages><namespaces><addnamespace="System.Web.Optimization"/><addnamespace="Microsoft.AspNet.Identity"/></namespaces><controls><addassembly="Microsoft.AspNet.Web.Optimization.WebForms"namespace="Microsoft.AspNet.Web.Optimization.WebForms"tagPrefix="webopt"/><addtagPrefix="ajaxToolkit"assembly="AjaxControlToolkit"namespace="AjaxControlToolkit"/><addtagPrefix="asp"assembly="AjaxControlToolkit"namespace="AjaxControlToolkit"/><addtagPrefix="cc1"assembly="AjaxControlToolkit"namespace="AjaxControlToolkit"/></controls></pages>

Below is my Content Place Holder page:

<%@RegisterAssembly="AjaxControlToolkit"Namespace="AjaxControlToolkit"TagPrefix="ajaxToolkit" %><ajaxToolkit:HtmlEditorExtenderTargetControlID="txt_largedesc"runat="server"/>

Below is my Master Page Script Manager:

<asp:ScriptManagerID="ScriptManager1"runat="server"><Scripts><asp:ScriptReferenceName="MsAjaxBundle"/><asp:ScriptReferenceName="jquery"/><asp:ScriptReferenceName="bootstrap"/><asp:ScriptReferenceName="respond"/><asp:ScriptReferenceName="WebForms.js"Assembly="System.Web"Path="~/Scripts/WebForms/WebForms.js"/><asp:ScriptReferenceName="WebUIValidation.js"Assembly="System.Web"Path="~/Scripts/WebForms/WebUIValidation.js"/><asp:ScriptReferenceName="MenuStandards.js"Assembly="System.Web"Path="~/Scripts/WebForms/MenuStandards.js"/><asp:ScriptReferenceName="GridView.js"Assembly="System.Web"Path="~/Scripts/WebForms/GridView.js"/><asp:ScriptReferenceName="DetailsView.js"Assembly="System.Web"Path="~/Scripts/WebForms/DetailsView.js"/><asp:ScriptReferenceName="TreeView.js"Assembly="System.Web"Path="~/Scripts/WebForms/TreeView.js"/><asp:ScriptReferenceName="WebParts.js"Assembly="System.Web"Path="~/Scripts/WebForms/WebParts.js"/><asp:ScriptReferenceName="Focus.js"Assembly="System.Web"Path="~/Scripts/WebForms/Focus.js"/><asp:ScriptReferenceName="WebFormsBundle"/></Scripts></asp:ScriptManager>

Calender Extender is coming from an Ajax tool kit, but getting issues with Ajax html editor.