Outlook VSTO Plugin does not show after install

2
votes

I've built and deployed an Outlook 2016 VSTO plugin and built an installer for it using the following walkthrough - https://msdn.microsoft.com/en-us/library/cc442767.aspx. The installer has been compiled for x86 and x64 architectures (two separate installs).

However, I'm seeing a variety of different issues when I install in different environments.

In a Windows 7 (x64, Office x32), the plugin loads as expected and works perfectly.

In a Windows 7 (x64, Office x64), the plugin installs, the LoadBehavior is correct, the plugin is loaded in Outlook but it is never displayed? I have tried to disable all other add-ins and still it doesn't show up?

I have tried using the suppressed alerts - How to troubleshoot a VSTO addin that does not load? - but this has not yielded any useful information at this moment.

Some of these peculiarities extend into Windows 10 itself.

What I'm trying to ascertain is why some environments the plugin goes in smoothly and in others why it fails or worst, faults. Are there other keys I need to look at?

Thanks

2
outlookvstooutlook-addin
Have you tried turning on 'show user interface errors' (File > Options > Advanced > Developers)? If it loads (I am guessing you are showing a message box or something during startup?) but your ribbon controls are not showing, that may be why. Not sure why it would only happen in a 64-bit environment though. – Chris

2 Answers

3
votes

There are a lot of pitfalls why you may not see the plug-in in Office applications.

The very first option I'd suggest checking - UI errors. By default, if an VSTO Add-in attempts to manipulate the Microsoft Office user interface (UI) and fails, no error message is displayed. However, you can configure Microsoft Office applications to display messages for errors that relate to the UI. You can use these messages to help determine why a custom Ribbon does not appear, or why a Ribbon appears but no controls appear. See How to: Show Add-in User Interface Errors for more information.

Second, make sure that you included all the required prerequisites to the installer. Sometimes the plug-in can't run correclty because any of the dependencies is missed. Or you just use platform-specific assemblies...

Third, make sure no exceptions are fired at startup.

Below you may find some helpful articles:

1
votes

Thanks for the info - the end result issue ended being a combination of registry keys being deployed to the wrong location for x64 platforms on an x86 Office install.

The solution was to cover my bases with both registry hives to ensure things loaded as expected.