Need to help guys. I'm having an issue with the single client MIDI over USB driver in Windows.

I've got use several DAW's (Realband, Calkwalk and Reaper) and have several muticlient audio interfaces (Focusrite, MOTU) and several MIDI interfaces (MOTU).

The problem I'm having is not with audio but with MIDI over USB. Not 5 pin DIN but with MIDI over USB. Regardless of which DAW I'm using and regardless of which interface I'm using when I open My VoiceLive 3 Extreme and my Voicelive Editor software at the same time the DAW is open, I get an error (Out of memory...even though I have 32Gb of memory).

I can run the Helicon VoiceLive 3 unit with the Editor software with no problem. I can run the Daw with the Voicelive 3 unit without the Editor software with no problem. I only get errors when I try to run the Editor software and one of the DAW's at the same time.

If I run the Helicon unit with 5 pin DINs, I have no problem. But the newest version of the Editor is USB only.

I have been told that this is happening because Windows MIDI over USB driver is single and not multiclient. I'm on Win 10 and 11 on my computer but have been told this has been a problem since WinXP with little to no improvement.

I have tried to use MIDIOx, LoopMIDI and LoopBe1but have had no success in addressing this.

Anybody have any thoughts on how to run MIDI over USB with more than 1 application?

Many thanks.

Jeff

@ Psychlist1972 < Pete from Microsoft is going to be your best bet of getting this answered.

Thanks for the pointer @ Scragend .

Yes, the current API implementations are single-client. There are some hacks for some devices where they implement multi-client in the driver, but to do it properly meant we had to rewrite MIDI on Windows from the ground up, which we are. New driver, new Windows Service (the older APIs go direct from API to driver and so have no way to plug into them), new API.

The new API we're delivering later this year is multi-client by default, and we're doing everything we can to plumb that back into the existing APIs so that, while they won't get all the goodness of MIDI 2.0, they'll get multi-client support. We need to do a ton of testing to ensure it doesn't break any existing apps, though.

We're also developing this in the open:
https://aka.ms/midirepo

And have a Discord server where we've been working with developers who are writing to the new API
https://aka.ms/mididiscord

For apps that use the new API directly, they also get outbound message scheduling, MIDI 2.0 features like increased resolution, new transports like Network MIDI 2.0, and more.

Pete

PS. I'm giving a talk and demo of the latest build of this next week at the NAMM Show, in the MIDI Association booth.

Thanks Pete, very much appreciate you taking the time to answer. This has been a very perplexing problem for me that has cost me literally weeks trying to solve. Happy to hear that a solution is coming later this year.

Jeff