BandInMusescore won't work

Hello there,

I am struggling to make BandInMusescore work but without success. I have followed the instructions found here https://github.com/berteh/BandInMuseScore. I still get the following error:

MMA accompaniment is ready for you, but we could not generate the MIDI file from it.
Please fix the following error:

C:\Program Files\MuseScore 3\bin>cd C:\WPython64\mma-bin-19.08\

C:\WPython64\mma-bin-19.08>..\PYTHON~1.AMD\python.exe mma.py -f C:/Users/username/AppData/Local/Temp/thermastis_MMA.mid C:/Users/username/AppData/Local/Temp/thermastis_MMA.mma

The generated MMA file is nevertheless available at "C:/Users/username/AppData/Local/Temp/thermastis_MMA.mma"

Any help would be much appreciated.
I enclose the file I am trying to work with.

PS: If the question is placed in an invalid thread, please redirect it accordingly, apologies for any inconvenience.