Application Object "Out Of Range" Error Initializing Legacy VB6 COM-Addin for Outlook 2013

Question

I'm attempting to ensure compatibility for an old VB6 COM-addin for Outlook 2013. It's worked fine (more or less) for every version since 2002 but in testing 2013 I'm getting an odd error when I attempt to initialize.

As soon as I try to take ANY action on the Outlook Application object I blow up with a "09 - Subscript Out Of Range" error. Even something as benign as casting the the olApp parameter I'm bringing into the class as a private var blows up. The Application object isn't null, it's property rich and seemingly initialized.

Friend Sub InitHandler(olApp As Outlook.Application, strProgID As String)

On Error GoTo ErrorExit

'If Outlook is opened without main UI (i.e. 'mailto:' HTML link)
If Explorers.Count = 0 Then Exit Sub

' BLOWS UP SO TRIED COMMENTING IT OUT AND ACCESSING PARAMETER DIRECTLY
'Set objOutlook = olApp

' ALSO BLOWS UP
Set objNameSpace = olApp.GetNamespace("MAPI")

...

Have there been any major architectural changes to the object model? Any ideas?

Answer 1

The issue here was that I needed to install the VB6 service pack 6 and cumulative rollout update.