I know the possible reasons why you might be having trouble opening the exported file, Gwynn.

First, if you're trying to open the file by double-clicking from the folder location, it is not possible since this is not a regular file, which results in an error.

If you want to review the file before importing it from the other company, you can right-click and open the file with Notepad or another medium file location.

To proceed, you can follow Step 3 in this article to import the exported IIF File to the new QuickBooks account: Export lists from the old company file into a new data file.

Here's the updated QuickBooks Desktop subscription price link for the new owner of your company: QuickBooks Enterprise Pricing.

I've added an article here where you have a guide if you only want to move your transactions: Copy multiple transactions from one company file to another.

If you have other exporting concerns or questions about managing your company data with QuickBooks, I'm always ready to help. Take care.