Windows 11 25H2 – MIDI port locked after closing djay Pro (midisrv deadlock)

Bug Reports
1

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  • Device model (e.g. 2020 iPad Air 4th Gen): PC Ryzen 7 9700x
  • Version of operating system (e.g. macOS 14.4.1): Windows 11 25H2
  • Version of djay (e.g. 5.1.2): 5.6.2
  • Hardware/controllers used (e.g. Reloop Mixon 8 Pro): Numark Scratch, MWM Phase Essential, DDJ-SP1
  • Hardware firmware version (e.g. 1.0.1): 9.0
  • Please consider sharing a short video or screenshots to help clarify your issue

Hello, I would like to report a reproducible MIDI issue in djay Pro on Windows 11 25H2.

System:

  • Windows 11 25H2 (clean install)

  • Latest version of djay Pro 5.6.2

  • Numark Scratch (native support, official driver)

Issue:

After a system reboot, MIDI works correctly on the first launch of djay Pro.

However, once djay Pro is closed and then opened again:

  • The MIDI device is still detected and visible in djay

  • But it does not respond at all (no MIDI input/output)

  • ASIO audio continues to work normally

  • MIDI remains non-functional until the computer is rebooted

Additional note:
Even other MIDI applications cannot use the device after djay has been closed. Only system restart helps.

Important:
The exact same hardware, drivers and djay version work perfectly on Windows 11 24H2 and previously on 23H2.

This issue only appears on Windows 11 25H2.

I’m not sure if the problem is only with the Numark Scratch mixer, but the DDJ-SP1 also stopped working (partially… the input was working but the leds on SP1 didn’t react). Nothing helps. Disconnecting devices, reinstalling Djay Pro. When I try to disable the device in Device Manager, the system freezes.

The same thing can happen simply by mapping new buttons. When you create a new MIDI map and click “Save,” the program stops responding to the device’s MIDI. Closing Djay Pro and reopening it doesn’t help, nor can any other program open the MIDI port to the Numark Scratch.

It looks like Djay pro doesn’t release the MIDI port for the device after closing the application.

After reinstalling the system on Windows 11 version 24H2, everything works without the slightest problem.

2

Hi @Damian_Zbroinski, thanks for the detailed info. It sounds related to this topic:

I will share this with our engineering team to see if they can reproduce the issue. I’m still using Windows 10 so can’t test on my setup.

5

Okay, but please note that the sound works. The ASIO driver from Numark Scratch loads every time and the music plays. MIDI simply stops working when I close the program and doesn’t allow MIDI to be used with this device until I restart the computer.

6

I realize they are not the same and understand that yours is a MIDI issue not an Audio issue. I mainly meant the 2 issues are directly linked to Windows 11 25H2. Either way, I have shared everything above with our engineering team for further review. Thanks!

1 Like
7

Thank you very much and have a nice day.

8

You’re welcome @Damian_Zbroinski. You too!

9

I think the problem is that in Windows 11 25H2, when you close Djay PRO, the application doesn’t close completely, because when you go into Task Manager, the application still appears open. What I do is force Djay PRO to close from Task Manager. Damián_Zbroinski, I think if you do that, you don’t need to restart the PC

1 Like
10

I’ve noticed this. The application sometimes stays open in the task manager, and sometimes it doesn’t. However, even killing the process doesn’t change anything, and the problem persists. The MIDI port remains blocked every time I close Djay Pro. I spent the entire evening trying various solutions, but nothing worked. Switching back to 24H2 resolved the issue.

11

Thanks for the additional info @djcanitamix and @Damian_Zbroinski