I created a Hyper Backup of my Synology's contents on a USB drive and I would like to access them with my Mac (directly via the USB drive).  The solution offered by Synology is their Hyper Backup Explorer app for the Mac (which provides for direct access & retrieval).  No problem loading the app but when I connect the USB drive to the Mac, I get the message "The disk you inserted was not readable by this computer".  I thought the problem might be an incompatibility with my M1 Mac, so I tried it on my older Mac; same result.

Any ideas?