VSTO Excel add-in not loading on terminal server

Question

My configuration is windows server 2003 (i'm logged in with admin privileges), office 2003, vtso runtime 2005 se. After installing my addin, all registry keys are in the correct locations and I have given fulltrust to my assembly using caspol.exe. My addin is a application level addin.

When I run excel with regmon and filemon running I can see that excel reads the registry keys of my addin, but I do not see the AddinLoader.dll being loaded in filemon. I get no errors from vsto since it doesn't appear the runtime is even starting up. I've read almost all of the vsto doco on msdn particularly the application addin architecture and vsto runtime overview as well as various other articles and discussions on the topic. I still can't figure out why the runtime won't load on the terminal server.

When installing this on an XP machine it all works fine and my addin gets loaded every time.

Anyone have any idea what might be preventing the vsto runtime from loading?

Answer 1

Never Mind I found that I was missing some registry keys after all. Got it working now.

For anyone that is looking for an answer to a similar problem then the registry keys you need to make a 2003 VSTO addin load for all users should look something like this:

[HKEY_CLASSES_ROOT\CLSID\{MY-EXCEL-ADDIN-GUID}]
@="MyExcelAddin -- an addin created with VSTO technology"

[HKEY_CLASSES_ROOT\CLSID\{MY-EXCEL-ADDIN-GUID}\InprocServer32]
@="Is vsdrvtEnvironmentString value type with "%CommonProgramFiles%\Microsoft Shared\VSTO\8.0\AddinLoader.dll" as its value"
"ManifestLocation"="C:\\Path\\To\\MyExcelAddin\\"
"ManifestName"="MyExcelAddin.dll.manifest"
"ThreadingModel"="Both"

[HKEY_CLASSES_ROOT\CLSID\{MY-EXCEL-ADDIN-GUID}\ProgID]
@="MyExcelAddin"

[HKEY_CLASSES_ROOT\CLSID\{MY-EXCEL-ADDIN-GUID}\Programmable]

[HKEY_CLASSES_ROOT\CLSID\{MY-EXCEL-ADDIN-GUID}\VersionIndependentProgID]
@="MyExcelAddin"

[HKEY_CLASSES_ROOT\MyExcelAddin]
@=""

[HKEY_CLASSES_ROOT\MyExcelAddin\CLSID]
@="{MY-EXCEL-ADDIN-GUID}"

[HKEY_CURRENT_USER\Software\Classes\MyExcelAddin]
@=""

[HKEY_CURRENT_USER\Software\Classes\MyExcelAddin\CLSID]
@="{MY-EXCEL-ADDIN-GUID}"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{MY-EXCEL-ADDIN-GUID}]
@="MyExcelAddin -- an addin created with VSTO technology"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{MY-EXCEL-ADDIN-GUID}\InprocServer32]
"ThreadingModel"="Both"
@="Is vsdrvtEnvironmentString value type with "%CommonProgramFiles%\Microsoft Shared\VSTO\8.0\AddinLoader.dll" as its value"
"ManifestLocation"="C:\\Path\\To\\MyExcelAddin\\"
"ManifestName"="MyExcelAddin.dll.manifest"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{MY-EXCEL-ADDIN-GUID}\ProgID]
@="MyExcelAddin"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{MY-EXCEL-ADDIN-GUID}\Programmable]

[HKEY_CURRENT_USER\Software\Classes\CLSID\{MY-EXCEL-ADDIN-GUID}\VersionIndependentProgID]
@="MyExcelAddin"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Excel\Addins\MyExcelAddin]
"Description"="MyExcelAddin -- an addin created with VSTO technology"
"LoadBehavior"=dword:00000003
"FriendlyName"="MyExcelAddin"
"CommandLineSafe"=dword:00000001

Of course you will need to change GUIDs and paths to appropriate values. By Putting the addin keys under local machine instead of current user the addin will work for all users without having to repair the install after running excel for the first time. Also this only lets the office application know the addin is there and that it needs to attempt to load it, this does not give the assembly trust in the system, you need to use Caspol.exe to do that. Read the msdn article about SetSecurty to do this http://msdn.microsoft.com/en-us/library/bb332052.aspx.