I am getting a message from Microsoft that the msixupload generated wont install on their test devices to get into the store.... How do you test a msix file because the msi file installs fine?
Before uploading the MSIX to the Store, you need to make sure that it can be successfully installed on your machine. Once the MSIX can be successfully installed on your machine, then you can start the upload process.
In your case, can you successfully install the MSIX on your machine?