Partner Center | Packages Upload Error

Tool: Microsoft MSIX Packaging Tool (ver: 1.2023.807.0)

Task: Using the MSIX Packaging Tool to build a MSIX package (file) containing an existing MSI file. When I drag or browse the file to upload, I get the file, size and an error off to the side and it never uploads. I have rebuilt, validated that the MSIX file does install correctly. 

Any help would be most appreciated.

Note: the next version of the application will have a MSIX file built out of the the IDE. This is a "one off" that needs to be done soon as possible, hence the hurry for an answer!