I'm trying to automate a few functions provided in a third-party xla. When I
open Excel normally, the add-in is available. I can invoke it via the UI or
VBA. When the Excel (2003) instance is created by VB.Net, the add-in is not
there. When I take user control of the Excel instance, the add-in is not
present (no UI, and it's not listed among the projects when I jump into VBA).
So of course I get a COM exception when my .NET code tries to invoke one of
the add-in's functions.
Again, the add-in is there when I launch Excel manually, but not when
launched via .NET. This works on another computer running different versions
of Windows and Office (the problem is on my desktop running Windows XP and
Office 2003). Any suggestions?