think i found my mistake.hyakken wrote: I tested on Windows7 with Reaper v5.32.
And it seems HY-MPS outputs midi event correctly when it'S gui is closed.
Which version of Reaper do you use?
i had the plugin on an empty track (without any midi-items).
in which case the seq fires midi when playback is started but only as long as the plugin window is open.
with a one-note midi item on the track it's spitting notes without the gui.