Then you should try to see what the value of SelectedItems(1) is... you might need SelectedItems(0).

Here's the thing... that whole File Picker dialog exposes you to a lot of different potential inputs, if you're not validating what you get back. Setting the .AllowMultiSelect to false is good... but then you need to make sure (I believe) that they've also selected a valid file (how do you know they didn't select a power point presentation?

I don't have access to a coding box here... but it sounds like you're on the right path. You're trying to have a way of getting the right info from a dialog picker... so focus on that. You don't have a MailMerge problem, yet.

In the immediate window, try typing:
?SelectedItems(0)
and
?SelectedItems(1)