Midi 2.0 - Patch: KB5077181 (Wind0 and 26100.7840 for versions 25H2 and 24H2)

[valis]

Just a heads up for Win11 users using loopback adapters (and very old MIDI devices), you may not be able to see those devices under the new MIDI subsystem that launched with Patch: KB5077181 (Wind0 and 26100.7840 for versions 25H2 and 24H2).

https://windowsforum.com/threads/window ... ul.400821/

https://devblogs.microsoft.com/windows- ... rkarounds/

If you dig through the above two links, you'll find the fix is 2 parts: ensure the driver(s) are listed underneath the 10 device limit, and then restart midi the new midi service to allow the 'old' drivers to load under the older codepath (which is why the 10 device limit is a necessary check in this case). To do this, close all midi client applications (audio and graphics like MMV etc) and start a elevated command prompt (run as admin), and then enter the following two lines:

net stop midisrv
net start midisrv

I use RTPMidi from Tobias Erichsen to communicate with RTP Midi on Macs. While technically not just a loopback, since it's a software midi driver it was also affected. Posting this here in case it helps others.

[Chilliman]

You don't need to do the command prompt thing really.
You can just go to services from task manager and restart windows midi services from there. I've added services as a shortcut in my start menu for now.
It's been doing my head in, it won't start the midi of my audio interface on startup. Temu midi thru box, fine, mvave Ali expressed wireless midi, no problem sir, novation SLmk3, not an issue, your audio interface and it's all
I will never understand why windows doesn't have proper competition.

[Rafe]

Copilot suggested :- USBDeview is a free, lightweight NirSoft utility for Windows that lists all currently and previously connected USB devices.

Cleaned up a few entries.
Seemed easy enough

[valis]

For older devices that are not able to use the new class compliant driver, this is important as you must keep the list of legacy devices in the first 10 midi devices for the API to enumerate them.

Copilot suggested :- USBDeview is a free, lightweight NirSoft utility for Windows that lists all currently and previously connected USB devices.

Cleaned up a few entries.
Seemed easy enough

[valis]

Update from a Microsoft dev on another forum, another KB fix is coming in April to resolve the loopback adapter initialization. He explained that he was looking for the port init calls but since some loopback drivers (and software drivers) init without any ports (because they are dynamically allocated) then the drivers did not get seen. A few other details in there for anyone who cares to scan the above link.

[valis]

Note that they have a checker utility up on the following url: https://microsoft.github.io/MIDI/get-latest/

If you scroll down to "Other Available Downloads" you'll find 2 sets of installers.

The second "Preview Network MIDI 2.0 Service Plugin" seems to be some new midi network protocol, no idea about its compatiblity with RTPmidi and other stacks in use, but it's interesting to see MS finally doing this for their OS. I'll probably stick with the open source RTPmidi on Win for now because I have a mixture of Mac, PC & Linux here and I can route across all via that protocol. But we'll see what this develops into, with cross platform support (and cross OS) it might be another viable alternative.

The first "Get the latest Windows MIDI Services runtime and tools" is more interesting for Korg USB midi users and others who have drivers using an old API that have a '10 device limit'. There were some freeware tools put out over the years that 'fix' an issue that occurs (and it might occur with the Korg installers as well, I can't recall). What happens is that the first registry entry winds up being midi0 (next is midi1...midi2...) and it should just be 'midi'.

This is discussed on this MS url: https://microsoft.github.io/MIDI/kb/req ... y-entries/

If you download and install the runtime/tools executable, you will get various tools installed as discussed on that same url (https://microsoft.github.io/MIDI/get-latest/), and there are instructions on the url above 'required registry entries' on how to use a command line tool "midifixreg" that should mitigate figuring out the 10 device limit issue for anyone that mistakenly created duplicated (or missing) registry entries after having problems with korg (and etc) drivers.

There are some other tools there worth exploring too to see if they're useful in your use case(s).

[Rafe]

Thank you

[valis]

After installing the latest "Windows MIDI Services runtime and tools" and then running the MIDI Utility it added to the start menu, it added default MIDI loopback adapters at the OS level as default. These will run under the MIDI 2.0 service fine.