Hi Igor,
I really don't know if Excel and Autodesk Inventor use the same mechanisms. What I know is that I made some Inventor-AddIns in the past including forms with iGrid, and there were no problems at all. I could send you a sample project, but you would need to install Inventor (there is a 30days-evaluation version). But I suppose that's too much effort for you.
I uninstalled all old iGrid components, installed the current demo and then the retail DLLs.
The 10tec reference in the project is the same as in a winform project where I have no problems.
I suppose there is no other reference needed for iGrid (not speaking about printing and filter)?
Unfortunately, the error message says nothing about which component is missing.
I also tried to create the grid by code
Dim myGrid As New TenTec.Windows.iGridLib.iGrid
, f.e. in a button-click-event, and the error message pops up when the click-event happens.