ASP.Net: Element <name> Is Not A Known Element - vb.net

Question

I've been trying to use the AutoComplete Extender from the ASP.NET Ajax Control Toolkit, however I've been having tons of trouble getting it to actually work.
To install the AjaxControlToolKit, I've placed it inside my application's bin directoy, then I just dragged and dropped the control into the form. However, it keeps saying,
"Element 'AutoCompleteExtender' Is Not A Known Element"
So at first, I thought I had not registered it yet, but when I looked at the header, it was already there:
<%# Register Assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35" Namespace="System.Web.UI" TagPrefix="asp" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" tagprefix="ajaxToolkit"%>
So I'm not sure at all, why its still giving me problems.
Other assembly files in my bin folder include:
System.Web.Extensions.ddl
System.Web.Extensions.Design.dll
Here's my code:
<asp:TextBox ID="txtOrganization" runat="server" Width ="500px" MaxLength ="250"></asp:TextBox>
<asp:ScriptManager ID="ScriptManager1" runat="server">
<Services>
<asp:ServiceReference Path="AutoComplete.asmx" />
</Services>
</asp:ScriptManager>
<ajaxToolkit:AutoCompleteExtender runat="server" TargetControlID="txtOrganization" ServiceMethod="GetOrganizationList" ServicePath="AutoComplete.asmx"></ajaxToolkit:AutoCompleteExtender>

Answer 1

I fixed it and got it working. I had to make changes to my aspx page and my web.config.
ASPX:
Added this to the top of my page:
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" tagprefix="ajaxToolkit"%>
My control now looks like this:
<asp:TextBox ID="txtOrganization" runat="server" Width ="500px" MaxLength ="250"></asp:TextBox>
<asp:ScriptManager ID="ScriptManager1" runat="server" >
<Services>
<asp:ServiceReference Path="AutoComplete.asmx" />
</Services>
</asp:ScriptManager>
<ajaxToolkit:AutoCompleteExtender runat="server" ID="AutoComplete1"
TargetControlID="txtOrganization"
ServicePath="AutoComplete.asmx" ServiceMethod="GetOrganizationList"
MinimumPrefixLength="1" EnableCaching="true"
FirstRowSelected="true">
</ajaxToolkit:AutoCompleteExtender>
As for my web.config, I added the following:
<configSections>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<system.web>
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</controls>
</pages>
<customErrors mode="Off"/>
<compilation debug="true" strict="false" explicit="true">
<assemblies>
<add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
<add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
</assemblies>
</compilation>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
<sessionState mode="InProc" cookieless="false" timeout="240"/>
<!--
The <authentication> section enables configuration
of the security authentication mode used by
ASP.NET to identify an incoming user.
-->
<authentication mode="Forms"/>
<!--
The <customErrors> section enables configuration
of what to do if/when an unhandled error occurs
during the execution of a request. Specifically,
it enables developers to configure html error pages
to be displayed in place of a error stack trace.
<customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
<error statusCode="403" redirect="NoAccess.htm" />
<error statusCode="404" redirect="FileNotFound.htm" />
</customErrors>
-->
<httpRuntime maxRequestLength="16000" useFullyQualifiedRedirectUrl="true" executionTimeout="180"/>
</system.web>
<system.web.extensions>
<scripting>
<webServices>
<!-- Uncomment this line to customize maxJsonLength and add a custom converter -->
<!--
<jsonSerialization maxJsonLength="500">
<converters>
<add name="ConvertMe" type="Acme.SubAcme.ConvertMeTypeConverter"/>
</converters>
</jsonSerialization>
-->
<!-- Uncomment this line to enable the authentication service. Include requireSSL="true" if appropriate. -->
<!--
<authenticationService enabled="true" requireSSL = "true|false"/>
-->
<!-- Uncomment these lines to enable the profile service. To allow profile properties to be retrieved
and modified in ASP.NET AJAX applications, you need to add each property name to the readAccessProperties and
writeAccessProperties attributes. -->
<!--
<profileService enabled="true"
readAccessProperties="propertyname1,propertyname2"
writeAccessProperties="propertyname1,propertyname2" />
-->
</webServices>
<!--
<scriptResourceHandler enableCompression="true" enableCaching="true" />
-->
</scripting>
</system.web.extensions>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<modules>
<add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</modules>
<handlers>
<remove name="WebServiceHandlerFactory-Integrated"/>
<add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</handlers>
</system.webServer>
Originally, since I'm using asp.net 2.0, the version numbers of System.Web.Extensions was 1.6.... So I had to change it all to 3.5.0.0.
Also, while searching for a solution, alot of people said I had to put a copy of System.Web.Extensions.dll and System.Web.Extensions.Design.dll into the bin folder. I didn't have to do this, I just merely added a reference to them.

Answer 2

Did you add a reference to it for the project?
Right click on the project from within Visual Studio...Hit Properties
Next to references you should see the AjaxControlToolkit in there...
If not, hit Add...got to Browse tab and select it.
I assume no other controls work?

Answer 3

Did you place a ScriptManager at the top of the page? You have to do this to get the Toolkit controls to work properly.
EDIT: There are many potential causes of this problem; you did not install the AJAX toolkit correctly, there are compilation errors in your site, etc. One of the more common problems is that you need to declare the toolkit in your web.config file. Inside the pages tag, add the following:
<controls>
<add tagPrefix="ajaxToolkit" namespace="AjaxControlToolkit" assembly="AjaxControlToolkit"/>
</controls>