Sorry if I arrive late and maybe with something that is neither pertaining.
This prb make me remember an issue that I experienced many sysupgrades ago for almost two subsequent times: sysupgrade suddenly stopped on the disk selection saying no acceptable disk destination was inserted while my usb disk of my station was clearly inserted and ready for the upgrade. The interesting parts here possibly addressing a suggestion for you are: 1) my problem replicated on different machines (almost 1 minipc and 1 laptop) and sticks (altghough coming from the same original installation) 2) to solve I copied the content of my stick to a larger usbdisk (almost 512gb by copy machine), upgraded the disk and copied back to the disk. It happened to me many years ago and when I was still with 16gb sticks, however I still own the same hardware. A side note: 7.5 upgrade on 32gb stick gave me no problem. -Dan
