I can share some information that can help you fix the error you're having, @RNewhouse.

To further check the cause of why you're not making or viewing payments made by Melio in QuickBooks Desktop, I highly recommend contacting their customer support team. They’ll be able to investigate the status of the payments and share steps to resolve the issue.

You can go to their website to check the contact details under the App information section: Melio app information. 

Here's also more information on how to enter the prepayments or deposits, either by using Accounts Payable or an Asset account in QuickBooks Desktop: Record vendor prepayments or deposits for prepaid parts or services. 

Don’t hesitate to post a comment if you have additional questions or concerns in making or viewing payments. I’ll be right here to answer them for you. Have a good one!