In a VSTO Runtime release earlier this year, we addressed an issue of slow application shutdown for add-ins using WPF controls on touch-enabled devices. With the release of .NET Framework 4.5.2 two months ago, and the increased usage of our latest runtime “in the wild”, we received customer feedback that the latest .NET 4.5.2 version interacts negatively with our latest VSTO Runtime version, introducing a different application shutdown issue.

Today, we’re happy to announce that we’ve quickly turned around a fix in the release of VSTO Runtime version 10.0.50701.  The update is cumulative, and includes both the previous fixes (addressing the touch-screen scenario) and the additional compatibility with .NET Framework 4.5.2.

As always, the latest version of the VSTO Runtime is available for download at http://go.microsoft.com/fwlink/?LinkId=140384.  The update will also be distributed as part of Windows Update in the upcoming months.  If you would like to ensure that your users have the latest version installed, please follow the instructions for creating/modifying a bootstrapper package from a previous blog post, substituting the latest version number (10.0.50701) into the following properties:

<BypassIf Property=”VSTORuntimeVersionInstalled” Compare=”VersionGreaterThanOrEqualTo” Value=”10.0.50701“/>

<BypassIf Property=”VSTORuntimeVersionOfficeInstalled” Compare=”VersionGreaterThanOrEqualTo” Value=”10.0.50701“/>

Again, many thanks to the developer community for bringing the issue to our attention, and helping us resolve this in a timely manner.

~ Michael Zlatkovsky | Program Manager, Visual Studio

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 http://dev.office.com or the Office Dev Blog for more information.

- Michael Zlatkovsky | Program Manager, Visual Studio

In the VSTO Runtime released a month and a half ago (version 10.0.50701), a small regression was inadvertently introduced, which is fixed in today’s update to the runtime.

The issue impacts add-ins that call Globals.Factory.GetVSTOObject on a Word document or Excel workbook.  If Windows Presentation Foundation (WPF) is used for the add-in’s user interface, and if the document or workbook corresponding to the “GetVSTOObject” function call is closed, the WPF UI Thread may shut down prematurely.  When this happens, rendering for WPF controls will be broken until Excel or Word restarted.  While this issue only manifests itself on certain system configurations (primarily touch-enabled devices) and only under very particular conditions, we recognize that this can be a serious scenario-blocker for certain add-ins.  Today, we are releasing a new version (10.0.50903) of the runtime that takes all the enhancements of the previous VSTO runtime release, but resolves this particular issue.

The update is cumulative and can be installed both on a clean machine and on top of an existing VSTO runtime installation.  As always, the latest VSTO runtime can be downloaded from our “permalink” at http://go.microsoft.com/fwlink/?LinkId=140384.  The update will also be distributed as part of Windows Update in the upcoming months.  In the meantime, if you would like to ensure that your users have the latest version installed, please follow the instructions for creating/modifying a bootstrapper package from a previous blog post, substituting the latest version number (10.0.50903) into the following properties in product.xml:

<BypassIf Property=”VSTORuntimeVersionInstalled” Compare=”VersionGreaterThanOrEqualTo” Value=”10.0.50903“/>

<BypassIf Property=”VSTORuntimeVersionOfficeInstalled” Compare=”VersionGreaterThanOrEqualTo” Value=”10.0.50903“/>

~ Michael Zlatkovsky | Program Manager, Visual Studio