default application for 'application/octet-stream'

[LJ808]

Help please!
When I plug a thumb drive into my Orange Pi 5 Plus I get this error message:

Failed to launch "16 GB Volume"
Failed to find default application for 'application/octet-stream'

I've done several searches and found same error message but the solutions don't apply. Any clues greatly appreciated. TIA

Also, I have Ubuntu 24.04.2 LTS installed and it's not updating to 24.04.3, even though I think I started with 24.04.1 from here and that seems to have updated. Ubuntu won't help me because they don't think I have Ubuntu but some fork off of it that they won't support.

GParted and lsblk -f both see it as a fat32 formatted drive. It mounts but won't open. It worked before I installed the OS to the eMMC and just ran off of the little card.