What you are suggesting is more back and forth between me and the user of my application which is exactly what I wanted to avoid as I feel I'm straining his willingness to help.

Yes, I was wondering about that aspect.
I guess the obvious solution is to get the user to communicate directly with us. But, of course, the user is fully entitled to refrain from doing so.
It sounds to me that you're much keener to find the solution than the user is ... which is unfortunate.
I'd like to find out what's happening, too. But, you're right to be respectful of the relationship you have with your user - and I understand that.

Cheers,
Rob