Hello therepetiteur,
[I've deleted you other, duplicate, post, since you've also posted the question here and people have replied here. Just for future reference, please only post each question in one place, so that people don't end up needing to reply in duplicate, and so that people replying can see any relevant previous replies from others.]
In case you haven't already found it, Snoize MIDI Monitor is a freeware utility that can show/log incoming MIDI messages:
https://www.snoize.com/MIDIMonitor/ . Make sure that no other MIDI applications (including Hauptwerk) are running when using it, since any given MIDI port should be open in only one application at a time.
As well as letting us know what MIDI messages the computer is receiving, what MIDI interface are you using? Is the MIDI interface connected to a USB hub, and, if so, does the USB hub have its own mains power supply connected? (Unreliable MIDI interfaces or USB hubs, or insufficient USB power are common causes of garbled MIDI messages.)
organsRgreat wrote:Further to Nick's point: some MIDI devices use active sensing, which generates a lot of extra data. I'm not sure whether Hauptwerk would automatically ignore that
Yes -- Hauptwerk just ignores MIDI active sensing messages.
Best regards, Martin.
Hauptwerk software designer/developer, Milan Digital Audio.