[BUG]: Phase DJ detected by Windows/Phase Manager but WIR intermittently unavailable in Serato on Windows 11 25H2
Closed
@Psychlist1972 is already working on this.
Since Sep 18, 2026.
bug :lady_beetle:
needs-investigation :mag:
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Description
Report pre-requisites
- I have searched this repo for existing issues to confirm this is not a duplicate
- I agree to follow this project's Code of Conduct
- I acknowledge that if I do not respond to follow-up questions in a timely manner, the issue may be closed without any changes or fixes
Clarity and Disclosure
- I confirm that any AI analysis included in this report is clearly called out / tagged as AI-generated with "AI Generated Content". Reports with suspected AI content may be closed if not disclosed.
- I confirm that I will quickly follow-up to questions or requests for additional detail, otherwise the issue may be closed
Windows Version
Windows 11 25H2, OS Build 26200.9457
Type of bug
- Windows doesn't recognize MIDI device (doesn't show in device manager)
- Application doesn't recognize MIDI device or ports
- Cannot update firmware on MIDI device (specify device, app, and firmware info)
- MIDI device is recognized, but cannot send or receive messages
- Sent or received MIDI messages are corrupted
- Application not working as expected
- MIDI 1.0 ports not named as expected
- Performance not as expected
- Localization issue (incorrect or missing language for Windows running something other than en-US)
- General application crash or hang
- MIDI Service crash or hang requiring Windows reboot
- Windows bugcheck / BSOD (please include in the areas below the device id from Windows Settings About page or a link to your crash dump uploaded to a sharing service)
- Other or Unsure (please indicate in additional notes section below)
Location
- Application using WinMM MIDI 1.0 (Classic API). Name provided below.
- Application using WinRT MIDI 1.0 (Windows 10 MIDI). Name provided below.
- Application using Windows MIDI Services API (sometimes referred to as MIDI 2.0). Name provided below.
- Other app/DAW/tool. Not sure about which API or SDK it uses. Name provided below.
- Windows MIDI Services tools like MIDI Settings, Console, etc.
- Directly in Windows MIDI Services SDK (for Developers only, please provide repro code)
- General Windows shell (Device Manager, Settings, Services, etc.). Name provided below.
- Windows MIDI 2.0 Class Driver (usbmidi2-acx.sys)
- Windows MIDI 1.0 Class Driver (usbaudio.sys)
- Vendor-provided MIDI driver (please provide details below)
- Other or Unsure (please indicate in additional notes section below)
Application Name and Version
Serato DJ Pro 4.0.9.3054
MIDI Device
MWM Phase DJ / Phase Essential, Receiver + 2 Remotes, firmware 9.0
Vendor Driver
No response
Output from the MIDI Diagnostics Tool
mididiag
========================================================================================================================
header
========================================================================================================================
This tool is part of the Windows MIDI Services SDK and tools
Copyright 2026- Microsoft Corporation.
Information, license, and source available at https://aka.ms/midi
Microsoft Windows MIDI Services - Diagnostics Report
ver_build_source : GitHub Preview
ver_build_name : SDK Release Candidate 4
ver_build_full : 1.0.17-rc.4.25
========================================================================================================================
os
========================================================================================================================
os_version : 10.0.26200
========================================================================================================================
processor_env
========================================================================================================================
PROCESSOR_ARCHITECTURE : AMD64
PROCESSOR_IDENTIFIER : Intel64 Family 6 Model 140 Stepping 1, GenuineIntel
PROCESSOR_LEVEL : 6
PROCESSOR_REVISION : 8c01
========================================================================================================================
native_system_info
========================================================================================================================
processor_architecture : 64-bit Intel/AMD
processor_level : 6
processor_revision : 0x8c01
------------------------------------------------------------------------------------------------------------------------
running_emulated : Native Intel/AMD x64 on x64 PC (Not Emulated)
------------------------------------------------------------------------------------------------------------------------
timecaps_min_period : 1
timecaps_max_period : 1000000
timer_resolution_min : 0.500 ms
timer_resolution_max : 15.625 ms
timer_resolution_current : 1.000 ms
========================================================================================================================
dev_mode
========================================================================================================================
dev_mode_enabled : true
========================================================================================================================
reg_drivers32
========================================================================================================================
reg_drivers32_entry : midi = wdmaud.drv
reg_drivers32_entry : midi8 = wdmaud.drv
reg_drivers32_entry : midi9 = wdmaud.drv
reg_drivers32_entry : MidisrvTransferComplete = 1
reg_drivers32_entry : midi1 = wdmaud2.drv
========================================================================================================================
reg_drivers32wow
========================================================================================================================
reg_drivers32wow_entry : midi = wdmaud.drv
reg_drivers32wow_entry : midi8 = wdmaud.drv
reg_drivers32wow_entry : midi9 = wdmaud.drv
reg_drivers32wow_entry : midi1 = wdmaud2.drv
========================================================================================================================
enum_winrt_midi1_api_input_ports
========================================================================================================================
========================================================================================================================
enum_winrt_midi1_api_output_ports
========================================================================================================================
endpoint_device_id : \\?\SWD#MMDEVAPI#MicrosoftGSWavetableSynth#{6dc23320-ab33-4ce4-80d4-bbb3ebbf2814}
name : Microsoft GS Wavetable Synth
========================================================================================================================
enum_winmm_midi1_api_input_ports
========================================================================================================================
endpoint_count : 0
------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
dev_caps_error_count : 0
========================================================================================================================
enum_winmm_midi1_api_output_ports
========================================================================================================================
endpoint_count : 1
------------------------------------------------------------------------------------------------------------------------
endpoint_index : 0
name : Microsoft GS Wavetable Synth
------------------------------------------------------------------------------------------------------------------------
dev_caps_error_count : 0
========================================================================================================================
enum_registry
========================================================================================================================
reg_current_config : Not present
reg_discovery_enabled : true
reg_discovery_timeout_ms : Not present
reg_use_mmcss : Not present
------------------------------------------------------------------------------------------------------------------------
reg_midisrv_exe : %systemroot%\system32\midisrv.exe
------------------------------------------------------------------------------------------------------------------------
reg_sdk_installed : C:\Program Files\Windows MIDI Services\Desktop App SDK Runtime\
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : (Midisrv Transport)
reg_transport_clsid : {2BA15E4E-5417-4A66-85B8-2B2260EFBC84}
reg_transport_dll : C:\WINDOWS\System32\Midi2.MidiSrvTransport.dll
file_version : 1.0.15.0
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : (Diagnostics Transport)
reg_transport_clsid : {ac9b5417-3fe0-4e62-960f-034ee4235a1a}
reg_transport_dll : C:\WINDOWS\System32\Midi2.DiagnosticsTransport.dll
file_version : 1.0.15.0
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : Midi2KSAggregateTransport
reg_transport_clsid : {0f273b18-e372-4d95-87ac-c31c3d22e937}
reg_transport_enabled : true
reg_transport_dll : C:\WINDOWS\System32\Midi2.KSAggregateTransport.dll
file_version : 1.0.16.1
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : Midi2KSTransport
reg_transport_clsid : {26FA740D-469C-4D33-BEB1-3885DE7D6DF1}
reg_transport_enabled : true
reg_transport_dll : C:\WINDOWS\System32\Midi2.KSTransport.dll
file_version : 1.0.15.0
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : Midi2LoopbackMidiTransport
reg_transport_clsid : {942BF02D-93C0-4EA8-B03E-D51156CA75E1}
reg_transport_enabled : true
reg_transport_dll : C:\WINDOWS\System32\Midi2.LoopbackMidiTransport.dll
file_version : 1.0.15.0
------------------------------------------------------------------------------------------------------------------------
reg_transport_name : Midi2VirtualMidiTransport
reg_transport_clsid : {8feaad91-70e1-4a19-997a-377720a719c1}
reg_transport_enabled : true
reg_transport_dll : C:\WINDOWS\System32\Midi2.VirtualMidiTransport.dll
file_version : 1.0.15.0
------------------------------------------------------------------------------------------------------------------------
========================================================================================================================
sdk_runtime_status
========================================================================================================================
sdk_runtime_initialized : true
========================================================================================================================
service_status
========================================================================================================================
available : true
========================================================================================================================
midi_clock
========================================================================================================================
clock_frequency : 10000000
clock_now : 47787516714
========================================================================================================================
enum_transports
========================================================================================================================
transport_id : {8FEAAD91-70E1-4A19-997A-377720A719C1}
name : Virtual Midi
transport_code : APP
version :
author :
description : Fornece suporte a MIDI (aplicativo para aplicativo) de dispositivo virtual para MIDI 2.0
------------------------------------------------------------------------------------------------------------------------
transport_id : {AC9B5417-3FE0-4E62-960F-034EE4235A1A}
name : Pontos de Extremidade de Diagn¾stico
transport_code : DIAG
version :
author :
description : Fornece os pontos de extremidade diagn¾stico loopback e diagn¾stico ping internos para MIDI 2.0
------------------------------------------------------------------------------------------------------------------------
transport_id : {942BF02D-93C0-4EA8-B03E-D51156CA75E1}
name : MIDI de loopback
transport_code : LOOP
version :
author :
description : Fornece suporte simples a MIDI de loopback de aplicativo para aplicativo
------------------------------------------------------------------------------------------------------------------------
transport_id : {26FA740D-469C-4D33-BEB1-3885DE7D6DF1}
name : Streaming de MIDI do Kernel para Drivers UMP
transport_code : KS
version :
author :
description : Fornece suporte a KS (Kernel Streaming) para USB MIDI 1.0 e USB MIDI 2.0 usando o novo driver de classe MIDI 2.0/UMP.
------------------------------------------------------------------------------------------------------------------------
transport_id : {0F273B18-E372-4D95-87AC-C31C3D22E937}
name : MIDIáde AgregaþÒo de Streaming de Kernel (KSA)
transport_code : KSA
version :
author :
description : Fornece suporte a KSA (Kernel Streaming) para drivers de streaming de kernel USB MIDI 1.0 agregados em um ponto de extremidade UMP.
------------------------------------------------------------------------------------------------------------------------
========================================================================================================================
enum_ump_api_endpoints
========================================================================================================================
endpoint_device_id : \\?\swd#midisrv#midiu_diag_loopback_a#{e7cce071-3c03-423f-88d3-f1045d02552b}
name : Service Test Loopback A
transport_code : DIAG
name_user_supplied :
name_endpoint_supplied :
name_transport_supplied : Service Test Loopback A
desc_transport_supplied : Diagnostics loopback endpoint. For testing and development purposes.
desc_user_supplied :
parent_id : SWD\MIDISRV\MIDIU_DIAG_TRANSPORT
parent_name : MIDI 2.0 Service Tests
------------------------------------------------------------------------------------------------------------------------
endpoint_device_id : \\?\swd#midisrv#midiu_diag_loopback_b#{e7cce071-3c03-423f-88d3-f1045d02552b}
name : Service Test Loopback B
transport_code : DIAG
name_user_supplied :
name_endpoint_supplied :
name_transport_supplied : Service Test Loopback B
desc_transport_supplied : Diagnostics loopback endpoint. For testing and development purposes.
desc_user_supplied :
parent_id : SWD\MIDISRV\MIDIU_DIAG_TRANSPORT
parent_name : MIDI 2.0 Service Tests
------------------------------------------------------------------------------------------------------------------------
endpoint_device_id : \\?\swd#midisrv#midiu_diag_ping#{e7cce071-3c03-423f-88d3-f1045d02552b}
name : Service Test Ping (Internal)
transport_code : DIAG
name_user_supplied :
name_endpoint_supplied :
name_transport_supplied : Service Test Ping (Internal)
desc_transport_supplied : Internal UMP Ping endpoint. Do not send messages to this endpoint.
desc_user_supplied :
parent_id : SWD\MIDISRV\MIDIU_DIAG_TRANSPORT
parent_name : MIDI 2.0 Service Tests
========================================================================================================================
ping_test
========================================================================================================================
ping_attempt_count : 10
ping_return_count : 10
round_trip_total_ticks : 6502
round_trip_average_ticks : 650
========================================================================================================================
*** Successful Run ***
========================================================================================================================
========================================================================================================================
end_of_file
========================================================================================================================
C:\Users\C8>
midiksinfo
===================================================================================================================================
This tool is part of the Windows MIDI Services SDK and tools
Copyright 2026- Microsoft Corporation.
Information, license, and source available at https://aka.ms/midi
===================================================================================================================================
Enumerating MIDI kernel streaming devices, using the MIDI class drivers or a third-party MIDI 1.0/2.0 driver.
Typically, these devices are USB, but other KS drivers will be included in the enumeration.
-----------------------------------------------------------------------------------------------------------------------------------
If the MIDI service is running when you run this utility, some devices may not report all pin properties because they are in-use.
To see MIDI 2.0 devices, you must stop midisrv (the MIDI service) before running this.
Use midi service stop or net stop midisrv from an Administrator command prompt to stop the service.
-----------------------------------------------------------------------------------------------------------------------------------
SDK Release Candidate 4 (GitHub Preview) -- 1.0.17-rc.4.25
===================================================================================================================================
No devices with MIDI pins found. This can happen if all devices are MIDI 2.0 and the service is running.
C:\Users\C8>
Repro
- I confirm that I was able to reproduce this issue using a simple app like
midi.exe,midi1monitor.exeorPocket MIDI - I tried but was unable to reproduce this issue using a simple application
Devices tested, and which ones fail
Phase DJ / Phase Essential Receiver with two Remotes, firmware 9.0.
Pioneer DJM-S11.
Both devices are connected directly to the laptop by USB.
Windows and Phase Manager detect the Phase device correctly.
The DJM-S11 is also detected correctly.
The failure is intermittent: Serato DJ Pro sometimes does not make Phase WIR/Wireless available on either deck after Windows startup, even though the Phase device is detected by Windows and Phase Manager.
AI Generated Content: Some wording and organization in this report were assisted by ChatGPT. All technical observations, tests, logs, screenshots and video evidence are from my own computer and my own testing.
Which MIDI API paths did you test?
| Path | Suggested tool | Result (works / fails / not tested) |
|---|---|---|
| Windows MIDI Services (MIDI 2.0 / UMP) | MIDI Monitor, or midi endpoint monitor |
Not tested directly |
| WinMM MIDI 1.0 (Classic API) | Serato DJ Pro 4.0.9.3054 | FAILS INTERMITTENTLY: Phase is detected by Serato/Windows, but WIR/Wireless is sometimes unavailable on both decks |
| WinRT MIDI 1.0 | MIDI Monitor | Not tested |
Additional test: Windows Legacy MIDI mode (UseLegacyMidi=1) was also tested. In this mode, the Pioneer DJM-S11 was no longer detected correctly by Serato, so I returned Windows to the normal MIDI Services mode.
API mode used when you saw the problem
Full Windows MIDI Services (0, the default)
Does the problem also happen in Legacy API mode?
None
Your personal observation that led to the bug report
Serato_session_log_[data-hora].log
Serato_session_log_[data-hora].log
Steps to reproduce
-
Connect the Phase DJ Receiver and Pioneer DJM-S11 directly to the laptop by USB.
-
Start Windows 11 25H2 with both devices already connected.
-
Wait for Windows to finish starting completely.
-
Open Phase Manager and confirm that the Phase Receiver and both Remotes are detected correctly.
-
Close Phase Manager without disconnecting or changing any USB cable.
-
Open Serato DJ Pro 4.0.9.3054.
-
Check the deck mode selector in Serato.
-
Intermittently, WIR/Wireless mode is not available on either deck, even though Phase Manager detected the Receiver and both Remotes immediately before opening Serato.
-
When the problem occurs, reconnecting the Phase USB cable, changing USB ports, or restarting/reopening Serato can sometimes restore WIR.
-
The issue is intermittent. After some complete Windows restarts, WIR is detected automatically, while after other restarts it is unavailable.
Additional notes
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Assessment
This issue has not been assessed yet.