My VSTO 3.0 Outlook addin doesn’t load

[Wayne]

[Sorry if this isn't the right forum for this... technically not VBA but this
is the closet forum I could find]

I'm trying to diagnose why my Outlook plugin written in C#/VSTO 3.0/VS 2008
doesn't load after being installed.

The plugin works awesomely on my development machine, which has Visual
Studio 2008 installed. I can't expect all my users to have all the
prerequisites though so I went through these steps to write an installer:
http://msdn.microsoft.com/en-us/library/cc563937(loband).aspx

I installed the add-in on a fresh Windows XP SP 2 machine with a fresh
install of Outlook 2007. It installs all the prereqs ok (.NET 3.5, VSTO 3.0
runtime, Windows Installer 3.1, 2007 PIAs). Outlook starts but the add-in
isn't run. If I go to the Add-ins tab in the Trust Center, I see my add-in in
the "Inactive Application Add-ins" section with the message "Not loaded. A
runtime error occurred during the loading of the COM Add-in.".

Not sure how to find the specific error so I can fix it.

The reg keys look ok. Under
HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins\BlahAddin I see
Description, FriendlyName, LoadBehavior (set to 3 until it fails after which
if becomes set to 2), and Manifest.

Tried the VSTO_SUPPRESSDISPLAYALERTS environment variable trick and then
launched Outlook from the command line but no output came out.

I have remote debugging more or less working but I'm not sure what to look
for. I don't see my DLL loaded when I attach to Outlook, but then again maybe
managed DLLs don't show up the same way in VS.

Any other ideas on next steps I could follow to produce a specific error I
can diagnose?

Thanks!

(Cross-posted to Stack Overflow, but still haven't figured this out:
http://stackoverflow.com/questions/1330282/my-vsto-3-0-outlook-addin-doesnt-load )

 

[Ken Slovak - [MVP - Outlook]]

Did you set the security? Without full trust a VSTO addin won't run.

If you did that and see the trust settings in the Framework configuration
tool you'd probably need to use Fusion logging and to study the logs to see
what's failing (Fusion is the managed code loader).

See
http://blogs.msdn.com/vsod/archive/2008/04/22/Troubleshooting-com-add-in-load-failures.aspx

There's also a managed forum specific to VSTO at the MSDN forums.