AJAX - TagPrefix is not registered

Question

I have looked at code on Unknown server tag "ajaxToolkit:HtmlEditorExtender" but am still stuck so would appreciate a second pair of eyes.

What I want to do is then, on submit, pass the HTML code to a string and save it. (I am only trying to get the HTML Editor to work at this point!)

Error: HTML EditorExtender. -- This control cannot be display because its TagPrefix is not registered in this Web Form

'######

I have tried adding

<pages>
              <controls>
                  <add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" />
              </controls>
          </pages>

But then pages comes up as invalid as well.

Newbie on AJAX.

I have

AjaxControlToolkit.dll in the bin folder as well as ajaxcontroltoolkit.pdb

Whole code below:

Default.aspx

<%@ Page Title="Default" Language="VB"  AutoEventWireup="false"  CodeFile="Default.aspx.vb" Inherits="_Default" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>

<%@ Register  
    Assembly="AjaxControlToolkit"  
    Namespace="AjaxControlToolkit.HTMLEditor"  
    TagPrefix="HTMLEditor" %>  

     <%@ Register
Assembly="AjaxControlToolkit"
Namespace="AjaxControlToolkit.HTMLEditor"
TagPrefix="HTMLEditor" %>

<asp:TextBox runat="server"
        ID="txtBox1" 
        TextMode="MultiLine" 
        Columns="50" 
        Rows="10" 
        Text="Hello <b>world!</b>" />


 <ajaxToolkit:HtmlEditorExtender ID="replyBody_HtmlEditorExtender" runat="server" Enabled="True" OnImageUploadComplete="saveFile"  ClientIDMode="AutoID" EnableSanitization="true"  TargetControlID="replyBody">

    <p>Test page shows</p>

Default.aspx.vb

Partial Class _Default
    Inherits System.Web.UI.Page

End Class

Web.Config

<?xml version="1.0"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
  <connectionStrings>
    <add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient"/>
  </connectionStrings>
  <system.web>
      <compilation debug="true" strict="false" explicit="true" targetFramework="4.0">


          <pages>
              <controls>
                  <add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" />
              </controls>
          </pages>


          <assemblies>
        <add assembly="System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
        <add assembly="System.Web.Extensions.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        <add assembly="System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
      </assemblies>
    </compilation>
    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login.aspx" timeout="2880"/>
    </authentication>
    <membership>
      <providers>
        <clear/>
        <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/"/>
      </providers>
    </membership>
    <profile>
      <providers>
        <clear/>
        <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/>
      </providers>
    </profile>
    <roleManager enabled="false">
      <providers>
        <clear/>
        <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/"/>
        <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/"/>
      </providers>
    </roleManager>
  </system.web>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>

</configuration>

Solution

You have this in your Default.aspx file:

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" 
    TagPrefix="asp" %>

Notice how you're assigning the tagPrefix of "asp" to the AJAXControlToolkit controls. You need to change that to this:

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" 
    TagPrefix="ajaxToolkit" %>

At that point, you can probably remove the line from the web.config (you don't need it in both places).