ASP.NET 3.5 and KB2533623, KB2507938

If I install either KB2533623 or KB2507938 on a Win 7 or a Win 2008, it kills my ASP.NET 3.5 application. The actual error I receive when loading the project is :

Invalid access to memory location. (Exception from HRESULT: 0x800703E6).

I don't have the full stack trace, but the error is coming from the LoadAllAssembliesFromAppDomainBinDirectory() call. Now the MS updates have made modifications to the way "insecure libraries" are loaded. My guess is that is causing me the problem. Removing these 2 updates will resolve the problem. It's not a machine specific problem, because this has happened on a total of 6 machines across 2 operating systems and managed by 3 different groups (so not just a bad image or something).

Assuming I need to secure my libraries, are we talking about just signing them? And if a 3rd party library is not signed, what then? Is there a way to tell ASP.NET to accept the libraries?

MSDN article http://msdn.microsoft.com/en-us/library/ff919712(VS.85).aspx talks about setting directories to load from. If this will resolve the issue, can I implement this before ASP.NET attempts to load all of the libraries from the bin folder?

Tony, I am not sure if following is the solution for you, but I don't have enough reps to put in a comment.

So some questions and suggestions:
1. On the front end do you get a HTTP 500 error?
2. Are these dlls in the bin folder of the web app?
If answer to any of above is yes, try this 'hack' -> Right click on the bin folder in Explorer and give [System]\Users access to the folder (where system is the name of the machine). First try with readonly, then try read write.

Normally your admin will baulk at doing this on production site. So someone will have to tell us how to 'actually' fix the issue. You could also try the solution for the user running the AppPool.

I have had 500 errors with Ajaxcontroltoolkit.dll in bin folder and this is how I have resolved it.

Hope this helps.