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 10, 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.
Issues
Issue: inMusic-branded companies’ drivers lock up the MIDI Service
Status: Workaround available on Discord. inMusic is working on the driver bug. Microsoft workaround goes into Windows at the end of April.
This causes apps like Cubase and other DAWs to hang when initializing MIDI, or closing ports, requiring a reboot to recover. In general, it can cause all MIDI devices to appear unresponsive. This is caused by nearly all the inMusic drivers including the m-audio drivers, AKAI drivers, RANE, Denon DJ, and others, regardless of device.
The service lockup happens when we try to close the driver. Other third-party drivers are fine, but these drivers (new and old, regardless of device) all lock up when asked to stop. The workaround going in-box closes these drivers in a different way. Note that these drivers can still crash the MIDI service if the device is disconnected or powered off while in use.
Bug: Dynamic ports (loopMIDI, loopBE, virtualTE / teVirtualMIDI / rtpMIDI) are not always visible.
Status: Preview Fix Available on Discord, in-Windows fix coming end of April
Problem: Third-party drivers which dynamically create MIDI ports in Windows do not work as before. Unless the ports were created before the service was started, they are not visible. Additionally, if you have more than 16 loopback ports defined in either loopBE or loopMIDI, only 16 will be available, and the names may be messed up.
The primary issue is the order in which the various components (the third-party product, the MIDI Service, the app) start up. But it can be difficult to align that in a way which functions in the way you want.
Known to affect:
- loopMIDI
- loopBE / loopBE30
- teVirtualMIDI (used by loopMIDI and rtpMIDI as well)
- Sonic Core software-defined MIDI ports
- te rtpMIDI
- IP MIDI
Possibly impacts
- SSL 360 link
- MPC Live III
- Possibly other AKAI apps
The problem is that the devices create the ports after midisrv has already started, and we don’t currently detect new ports added to an existing device.
Bug: WinRT MIDI 1.0 Timestamps are in the future, so no messages received.
Status: Preview Fix available on Discord. In-Windows fix coming at end of April
This impacts djay Pro as well as Cakewalk Sonar and Steinberg Cubase when set to use WinRT MIDI.
Issue: Some apps may connect to the wrong device if you have multiple identical MIDI devices with the same names
Status: Preview fix available. In-Windows fix coming at the end of April.
Issue: VirtualDJ Not able to communicate with controller
Status: Fixed by VirtualDJ, Windows workaround went out starting at the end of March
We have worked with VirtualDJ on this, and would like to thank them for their cooperation and quick response.
The new MIDI stack is much faster than the old one, so we’re finding that some apps are running into errors that they hadn’t previously run into. In the case of VirtualDJ, this results in the UI freezing up.
Issue: Old Hercules and possibly other brand controllers using DirectMusic drivers are not compatible with Windows MIDI Services.
Status: DirectMusic is not supported by design. Please see GitHub issue 962
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.
The new Windows MIDI Services stack does not load the older-style .DRV WinMM drivers and 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.
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
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