Did you check your MiST for a newer Firmware?
I got a older MiST with newer Firmware where the MSX2-Core did work and a newer MiST witrh older Firware which didnt load the MSX2-Bios
I retested - but with my "old" MiST (got 2 MIDI-MiST) which I did buy one year ago - and the same SDCard with hangs on the newer MiST- do work on the older MiST and MSX2-Core.
So it can be the MiST itself or only the Firemware-Version.
The working MiST shows me as FW (Firmware) s/w ver. ATH160721 on my older MiST
My newer MiST - which I did buy 4 Months ago - shows a old FW:
s/w ver. ATH151118
You could try to use a newer Firmware from:https://github.com/mist-devel/mist-bina ... r/firmware
[EDIT] Hmm.... updated the newer MiST also to ATH160721, but the MSX2-Core isnt loaded ;( Also not with the newer firmware_160910...