Hi. This post features prominently in google for people looking to upgrade their MBox 2 to a version that works in Linux. 1.38 is sufficient for this purpose with kernels 5.0.0 and above. Which is good, because the 1.43 firmware updater just doesn't work, regardless of how you execute it.
Kudos to Avid for keeping old binaries around, and allowing me to get my old MBox 2 from the 1.1 series up to 1.38 and keep it out of the landfill.
Some one else had the same problem:
https://gist.github.com/vectorsigma/...ef6c9c2686797b