Hi. I have just created a MIDI file in MuseScore. When I import it into Piano Booster, all of the notes are correctly imported, but the speed is at least 10 times (maybe closer to 50 times) slower than it ought to be (and since I cannot increase the speed to more than about 200% in Piano Booster, the score is not playable). The file is played by Windows Media player at the correct speed, so I don't think it is a problem with the MIDI file. I would include the MIDI file in question, but there doesn't seem to be a way to attach files on this forum.
I have found the bug in PB which I am fixing. As there is no tempo
defined in your midi file then PB does not correctly set a
default tempo of 120 bpm when the tempo is missing. If you set a tempo
in your midi file then that should fix your issue.