Outlook Add-In Loading Problems

[Brian Nicholson]

Hello,

We have recently developed a simple add-in for Outlook developed in VSTO for
a number of our users, but with a few of the users, the add-in simply doesn't
load.

Currently, we have a setup package that installs the necessary keys in HKLM
and the necessary FullTrust code group in My_Computer_Zone. The add-in
creates a simple 2-button toolbar in Outlook. We tested the add-in on a
number of machines before pushing it, and it worked on all of them. After
pushing to approximately 30 users, however, we found that add-in toolbar did
not appear for several people (at least 4-5 that we are aware of).

Here’s where we are stuck: we attempted to fix the issue by installing the
add-in manually for each user. After installation, the add-in works as
expected under the Administrator account used for installation. If we log on
to a test account which has normal user permissions, the add-in also appears
as it should. However, when the computer’s main user attempts to load the
add-in, it still doesn’t load. We’ve tried completely uninstalling and
reinstalling to no avail. We’ve also tried logging to a file when the add-in
loads, but even this entry doesn’t show up, so it seems there must be some
setting/program on the user’s account which prevents the add-in from even
beginning the load process.

Our initial reaction was that VSTO or some other necessary dependencies
didn’t exist on the users’ computers, but the fact that the add-in works on
all accounts except for a single user has killed that theory. What could be
the cause of this?

Thanks,
Brian

 

[Ken Slovak - [MVP - Outlook]]

What version of Windows are the problem users using? Are they under UAC if
this is with Vista? Did you look at the information about what you have to
do for VSTO addins to get them to correctly install and run when registering
to HKLM?

 

[Brian Nicholson]

Most of the users have Windows XP, but a few have 2000 -- none have Vista.
Also, I forgot to mention that this is for Microsoft Outlook 2003. As far as
I know, for Office 2003, all you have to do is put the same HKCU keys into
HKLM, correct? It seems like this would be set up correctly since the
problem only occurs for a single user on the machine.

 

[Ken Slovak - [MVP - Outlook]]

No, it's not that simple. Out of the box VSTO does not support installation
in HKLM, only in HKCU. There are articles about how to get VSTO to support
installation in HKLM.

 

[Brian Nicholson]

I've been trying to find articles on HKLM in Office 2003, but most of the
articles I find seem to address only Office 2007. One of the first articles
I came across when developing the add-in was the following,

http://blogs.msdn.com/mshneer/archive/2007/09/04/deploying-your-vsto-add-in-to-all-users-part-i.aspx

where the author says:

Office 2003 does not have a native notion of managed add-ins. So all COM
add-ins (even VSTO add-ins for Office 2003) can be registered under HKLM hive
(e.g. HKLM\Software\Microsoft\Office\Excel\AddIns\MyAdd) which will work for
machine-wide deployment - and this is how machine wide deployment of add-ins
has been done in the past.

If this is incorrect, could you perhaps point me in the right direction?

Thanks.

 

[Ken Slovak - [MVP - Outlook]]

Misha's blog posts were what I was thinking of. There are comments below the
blog posts about how all that he said relates to Outlook 2003. Make sure to
read everything and follow it very closely.