This has come up before, but I’m not sure we ever figured out the cause. I’m not sure what version of the software the PicoCalc ships with these days but it’s likely both the BIOS/firmware for the keyboard/STM32 are old and the PicoMite version is probably old and buggy as well. Not sure if either of these would cause this problem, but updating to the latest version would likely avoid other problems.
This might also be related:
Last time, when the files were downloaded from github a certain way it worked (see the first thread). So it might just be with how you downloaded the source files you’re trying to use and somehow they are getting mangled?