ASP.NET Website is not longer working after the latest Windows Updates

Our ASP.NET website uses some external assemblies like AjaxControlToolkit.dll, AjaxMin.dll, DocumentFormat.OpenXml.dll and some more. They are registered in the References-Node. All worked fine, but after the latest windows Update, I got the following error:

Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. Strong name signature could not be verified. The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. (Exception from HRESULT: 0x80131045)

If I check the AjaxControlToolkit.dll with the tool sn.exe, it shows, the dll is valid. I have also tried to compile the AjaxControlToolkit with the source code. I have signed it with a strong name and the sn.exe has shown valid. I have tried to install ist to the global assembly cache with the gacutil.exe, but this fail although with the same problem, it has a problem with the strong name, also i have self compiled and signed and so on.

But it is not the problem, because, if i remove the AjaxControlToolkit.dll from the bin folder of the website, running in iis, then, the next dll creates the same error, the AjaxMin.dll could not be loaded.

If I remove the AjaxMin.dll, the DocumentFormatOpenXml.dll created the same error.

We are using Visual Studo 2010 and we have hosted our website in Windows Server 2008 R2.

Kind regards

I was able to resolve this by redownloading the binaries from CodePlex. http://ajaxcontroltoolkit.codeplex.com/downloads/get/116533