VS2012 .NET 4.0 Clickonce VSTO CryptographicException: SignatureDescription could not be created for the signature algorithm supplied

Question

I have a VS2010 .NET 4.0 VSTO Outlook Addin project that I wish to migrate to VS2012 (but keep it in .NET 4.0). It compiles fine, and runs from inside the IDE just fine, bu

Answer 1

I solved my problem by creating a new certificate that is used to sign the ClickOnce manifest and generated it using the SHA1 algorithm. You can see the conversation here: http://social.msdn.microsoft.com/Forums/en-US/winformssetup/thread/eba424ae-f7b7-4530-bb68-db3b9972a31e

Edit 2014-Aug-05:
Visual Studio 2013 Update 3 finally fixes this problem.
http://support.microsoft.com/kb/2933779
From Fixed Issues -> General:

You can use SHA 256 code-signing certificates even for applications that target the .NET Framework 4.0 or an earlier version. Before this update, the .NET Framework 4.5 had to be present on the client computer when a SHA 256 code-signing certificate was used for desktop applications published with ClickOnce or Visual Studio Tools for Office add-ins. If you have used SHA 256 code-signing certificates in the past, and have seen errors such as "The application is improperly formatted," "The manifest may not be valid," "Manifest XML signature is not valid," or "SignatureDescription could not be created for the signature algorithm supplied," this update resolves the problem for re-published and newly-published applications.