Visual Studio 2013 Update 3 released

Earlier today, Visual Studio 2013 Update 3 was released.  This update offers a number of small but useful enhancements for VSTO developers:


#1:  Support for .NET 4.5.2 and beyond, and the de-coupling of Office versions from .NET versions.

We heard a lot of feedback on this on MSDN forums, with developers asking to mix-and-match versions of Office with versions of .NET Framework.  With the latest update, the .NET Framework and Office versions are fully de-coupled:  both the Office 2010 and 2013 project templates can work with any of the 4.0+ .NET Framework versions (.NET 4.0, 4.5, 4.5.1, 4.5.2, and beyond).


#2:  Better design-time support for SHA256 code-signing certificates.

In the past, using a SHA256 code-signing certificate would require a runtime dependency on having .NET Framework 4.5 or above installed on the runtime machine.  Running the program without .NET 4.5 installed would result in an error:  “Exception reading manifest …  System.Deployment.Application.InvalidDeploymentException: Manifest XML signature is not valid. —> System.Security.Cryptography.CryptographicException: SignatureDescription could not be created for the signature algorithm supplied.”

With the latest update, Visual Studio now generates a manifest in a way that can be read and run by .NET 4.0, even if the certificate happens to be SHA256.


#3:  Easier unit-testing.

One question I’ve often heard is about unit-testing VSTO projects.  Part of the confusion was caused by VSTO projects not appearing in the “Add Reference” dialog.  Unit-testing VSTO projects would therefore require creating a separate class library project, moving code into it, and then referencing this class library from both the VSTO project and the Unit Test project.  While this separation made sense for complex projects, it was overkill if all you wanted was to unit-test a handful of classes and methods.

Starting with VS 2013 Update 3, the “Add References” restriction for VSTO projects has been removed:  you can now create a Unit Test project and reference the VSTO project directly, without the intermediary step of moving your code to a separate class library project.


We hope you find these updates a welcome addition to your Visual Studio 2013 experience.  And, of course, for those interested in the new apps for Office & SharePoint model or in the Office 365 APIs, there’s a variety of tooling enhancements and platform capabilities that went into Visual Studio 2013 Update 2 a few months back (and included in this cumulative Update 3).  Check out or the Office Dev Blog for more information.


– Michael Zlatkovsky | Program Manager, Visual Studio