This is a post to assist customers with known bigger issues or workarounds, in the interest of remaining transparent on this project and unblocking customers and companies. Please see links below to our Discord server for further discussion and workarounds.
Updated April 30, 2026.
Main Windows MIDI Services Announcement blog post
The issues and workarounds here apply only to the new Windows MIDI Services rollout in Windows 11 retail 24h2, 25h2, and 26h1. This does not apply to older versions of Windows. Insider builds get different releases on a different schedule so this information may or may not apply to a Windows Insider Canary/Dev/Beta release.
We performed multiple years of testing with customers, partners, and our own equipment over the development cycle for Windows MIDI Services, but some bugs have made it through, as is known to happen with software development. We’re working on them in priority order, but I wanted to ensure the most impactful ones have more detail here.
Full issue list and updates for bugs, feature requests, and more may be found on our GitHub Repo
For support, questions, and workarounds, please join our Discord Server. That is the best place for us to help you out, and has the most up-to-date info.
Important Note
If you are using CFR (Controlled Feature Rollout)-disabling tools like the vive tool or the “disable MIDI 2.0” button in an app like VDJ, that will stop working at the end of April when the January release of Windows MIDI Services comes out of CFR. Each bug fix since January has been released as a CFR at the end of each month. Uninstalling those updates generally results in uninstalling the bug fixes and resulting in a worse or completely broken MIDI experience. So please do not uninstall updates.
If you are stuck, we have workarounds or fixes for all the major issues available on the Discord server above. However, for those to work, you will need to be up to date with your Windows updates.
Issues
Issue: inMusic-branded companies’ drivers lock up the MIDI Service
This fix has started rolling out today, April 30, via the 30 day CFR process.
Bug: Dynamic ports (loopMIDI, loopBE, virtualTE / teVirtualMIDI / rtpMIDI / NI Service) are not always visible.
This fix has started rolling out today, April 30, via the 30 day CFR process.
Bug: WinRT MIDI 1.0 Timestamps are in the future, so no messages received.
This fix has started rolling out today, April 30, via the 30 day CFR process.
Issue: Some apps may connect to the wrong device if you have multiple identical MIDI devices with the same names
This fix has started rolling out today, April 30, via the 30 day CFR process.
Issue: Old Hercules brand controllers using DirectMusic drivers are not compatible with Windows MIDI Services.
Status: DirectMusic is not supported by design. Please see GitHub issue 962
The DirectMusic API was deprecated with Windows Vista 20 years ago. The only reason it has worked since then, is because our MIDI stack in Windows has had no real changes in that time. There are very few devices out there which used custom drivers using the DirectMusic API and driver model, but some of the older Hercules devices do.
We won’t be able to write this ourselves, but because the Windows MIDI Services stack is open source, we’d be willing to accept a PR from someone who wants to write a Windows MIDI Services transport that can talk to these devices. We want to be as backward compatible as possible and support as many devices as possible.
To also better handle situations like this, we will ship the ability to revert back to the old MIDI stack starting at the end of June. That won’t receive any other updates, and won’t have access to the new transports or tools, but will be able to support these very old devices. We can’t promise that this option will always be available in the years to come.
Known to impact: – DJ Console Mk2 – DJ Console Mk4 – DJ Console Rmx – DJ Console 4-Mx – DJ 4Set – DJ Control Steel – DJ Control MP3 -DJ Control MP3 e2 / MP3 LE / Glow
General Issues
Issue: Korg USB devices using a .DRV winmm-style driver are not recognized
Status: By design, but these USB devices will work if you use our in-box drivers. There is no plan to change this behavior.
When an old-style KORG USB driver is included in the registry, our backwards-compatibility code tries to load it. This conflict with the MIDI service also loading the USB device. This may cause the device to not appear, or in some cases, apps using MIDI to take a very long time to list devices, appearing to hang. Luckily, there’s very little need for those old-style drivers anymore as the new stack is fully multi-client and supports class-compliant USB MIDI devices.
Korg has issued news bulletins explaining that their USB drivers are no longer required and are not compatible with the new MIDI stack.
You can continue to use the KORG BLE driver, but note that the uninstallers/installers can mess up registry entries. Join the Discord Server for help if you run into this. In addition, the MIDI Settings app, as of Release Candidate 4 (rc4) includes a one-button fix for registry corruption.
Fix
Completely uninstall and remove the driver. This can be tricky with the Korg drivers in-particular because they tend to cause issues in the registry. We have complete instructions on our Discord Server in the #workarounds-and-instructions channel.
These are the only required registry entries for Windows MIDI Services.
Issue: Korg devices using the Korg BLE driver may not show up.
Status: This can be caused by driver uninstallers/reordering tools. Instructions below on how to fix this.
Instructions
We will eventually have a first-class BLE MIDI 1.0 transport in Windows MIDI Services. Today, you can continue to use the Korg driver for BLE MIDI (we do not recommend using their drivers for USB MIDI as those conflict with the USB MIDI Support in the MIDI Service).
Because the Korg BLE MIDI driver is an older style WinMM driver, it needs to be loaded in addition to the new Windows MIDI Services wdmaud2.drv. Because of this, it will not appear in any of the tools provided with Windows MIDI Services and will not be multi-client.
After installing the latest Korg BLE MIDI driver, the registry should have the following entries
Open regedit and paste this location into the address bar at the top of the app
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32
You should see these entries:
- midi REG_SZ wdmaud.drv
- midi1 REG_SZ wdmaud2.drv
- midi2 REG_SZ korgbm64.drv
Here’s the explanation of what those entries do
- wdmaud.drv provides the in-box MIDI 1.0 synthesizer
- wdmaud2.drv provides the Windows MIDI Service and all USB devices, loopbacks, and more.
- korgbm64.drv provides the Korg BLE MIDI 1.0 devices
With those entries in place, all your devices should be working with 64 bit apps (we have on Discord more information for 32 bit apps like MIDI-OX). There should be no other Korg .drv files in that list. Also note that “midi0” is not a valid entry. That entry needs to be named “midi”.
Other Important Notes
Do not use the Korg Driver Uninstaller or any other tool which works to change the ordering of midi…midi9 entries in the registry. Windows MIDI Services requires only that midi is set to wdmaud.drv and midi1 is set to wdmaud2.drv. If those two entries are not present, Windows MIDI Services will not work on your system. The SDK runtime and tools includes a tool midifixreg which will ensure these two settings exist, in case you’ve already run one of these tools on your system.
How to File Bugs or Report Issues
Please do not comment on this post with issues/bugs/questions/complaints.
Questions/Discussion, and for customers without access to GitHub, issue reporting: https://aka.ms/mididiscord . Be sure to read the post in #start-here that the invite lands you on.
Developers and anyone else with access to GitHub can file issues here: https://aka.ms/midirepoissues
Hello ,
I use Samplitude Pro X8 as a DAW; I had installed RtpMidi in order to communicate with TouchDAW installed on my Android tablet (version buyed).
Everything was working fine until a few days ago; since then, the virtual ports no longer appear in Samplitude, Cubase, or any other DAW.
However, sessions 1 and 2 that were created are still visible in RtpMidi.
But in my DAW, I only see "keyboard" as MIDI input and "Microsoft GS Wavetable Synth" as output.
I use my Allen & Heath QU-SB mixer as a sound card.
Can you please help me?
Thank you...
Answered on Discord. Thanks for posting there!
Pete
Microsoft
I’d love to join your Discord server, but when I follow the link to it, Discord tells me
Invite invalid
This invite may be expired, or you might not have permission to join.
Suggestions?
I just double-checked and the invite link is still valid. Anyone should be able to join. But you need to use the main invite link, not a deep link into an entry unless you already have already joined.
https://aka.ms/mididiscord is the link.
Pete
Microsoft
Figured it out. It’s not enough just to follow that link; you have to log into Discord, tell it you want to join a server, then paste the link into the dialog box that results. Kind of weird, but now it works. Thanks!
Hi Pete,
I have a Korg Kronos with the driver USB Midi installed (Version：1.15 r63e Date：2026.01.20) but your workaround describe for .DRV does not work.
I have run midifixreg and have verified the registry after uninstall the Korg drive but my Kronos does not appear in the windows midi tool after some reboot and starrt stop of midi service.
Please help. I am searching a solution for 2 days now.
Thanks
I finally found the solution in the Discord thread “Difficulty inializing KORG MIDI Functions” by removing Kork oemXX.inf driver manually.
Thanks
Everything Microsoft touches turns to ….
Currently running a Rane Performer+Serato and this has caused me massive issues.
I wiped my machine and re-installed everything which took 2 days of my time. I’m nervous to gig live with this windows machine.
I can get things to work only once it first boots but I can never quit the software without a crash or turn off the controller. This means my library can get currupted when trying to exit.
Really need this fixed ASAP.
As mentioned above:
Questions/Discussion, and for customers without access to GitHub, issue reporting: https://aka.ms/mididiscord
There are workarounds there and ways to get you back to functional. Check the #start-here channel.
Pete
Microsoft
Is there any planned release for aggregate devices in Windows? My most wanted feature that has been discussed in one of your past blogs.
I assume you’re talking about audio (this blog post is about MIDI). As stated in the past, it’s under consideration for audio, but there are no immediate plans, and it will not be in the UAC2/ASIO driver 1.0 release.
Pete
Microsoft
It took me three days to figure out why my dj controller wasn't working with Rekordbox... After the recent Windows update / Windows MIDI Services rollout, my DJ controller (Pioneer DJ / AlphaTheta DDJ-1000) was no longer correctly recognized by DJ applications when the controller was powered on after the application has already started. After uninstalling KB5077181, rekordbox again detects the DDJ-1000 even when the controller is powered on after the app starts. However, I didn't immediately think of the workaround (starting the controller first and then the app). For less inquisitive or less technical users, this could result in...
This whole situation has been BENDING me over the past few days holy smokes
Hello Pete, i’m in trouble. loopMIDI was working correctly, but this morning it disappeared from the system. I’m on the latest Windows 11 25H2 release and I use a Stream Deck with Ableton. I had been struggling with this issue because I was on a Windows Beta version. I managed to install the official Windows release, and everything worked correctly for two weeks. This morning loopMIDI disappeared again.
I haven’t installed any new hardware or drivers, except for my graphics card drivers. I uninstalled loopMIDI, cleaned the registry, and reinstalled it, but nothing changed — loopMIDI is not detected in Device...
Hi Roberto
Blog comments aren’t any good for debugging an issue, and I’d need much more info to help you out. Can you join https://aka.ms/mididiscord and create a new thread under midi-user-questions please?
Pete
Microsoft
Hi Pete,
> after you install the KB which contains the Windows MIDI Services binaries, you will get the new feature enabled at some point
Does it mean we get another one update that will enable the Windows MIDI Services? If not, how it will be done? I hope MS cannot remotely manage my PC 🙂
Updates can be enabled or pulled if, for example, it turns out it’s breaking PCs, or in this case, to control the pace of a feature rollout.
I do not know what that mechanism looks like or exactly how it works, but it’s likely through Windows Update.
Pete