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I am unable to get the List Search Extender from the Ajax Control Toolkit to work correctly. After inserting my WebPart to the page, I get the error: "Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. The system cannot find the file specified."

I followed the installation instructions for Visual Studio 2010 as found here. I see the AjaxControlToolkit listed in the references section of my solution and I have registered the assembly as shown in my code below.

*EDIT: Additionally, the assembly shows up in the GAC and I added a screenshot of the assemblies in my project package and the corresponding safe control in the Web.config

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

<asp:ListBox ID="VendorSelector" runat="server"></asp:ListBox>
<asp:ListSearchExtender id="LSE" runat="server"
  PromptText="Type to search"




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Is the assembly in the GAC? If so, you need to use the full 4 part assembly name (the one with the PublicKeyToken and stuff). – James Love Aug 5 '12 at 21:28
Thanks! I updated the post to reflect your comment. – James Grizzle Aug 6 '12 at 13:25

It appears that the version of the AJAX toolkit you are using is incorrect. I had this issue and after downloading and installing the correct version for my target sharepoint installation, and it worked. Hope this helps.

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up vote 0 down vote accepted

I added the version and public key of the assembly in my Register statement. No more runtime errors.

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I should also note that beware when adding assemblies to the project using that interface - if any other solutions rely on that assembly and you retract your solution, it will pull out that assembly from the GAC and break the other solutions. – James Love Aug 6 '12 at 15:38
Good advice; thanks! – James Grizzle Aug 6 '12 at 16:36
also when adding any dll to the gac allway do an iis reset! – ali Sharepoint Oct 15 '12 at 8:03

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