In case this helps anyone, this is what I had to do to get S4 working on windows 11.
S4 MK1 dark in Traktor Pro 2 on Windows 11 (only MASTER/USB LED lit): fixed by installing Controller Editor
Setup: Traktor Kontrol S4 MK1, Traktor Pro 2.11.3, S4 driver 3.1.0, firmware 15, Windows 11 25H2.
Symptoms:
- S4 LEDs flash once when plugged in, then only the MASTER/USB LED stays lit
- Audio through the S4 works, and the S4 driver control panel says "Interface connected"
- Traktor's Setup Wizard says "All connected Native Instruments KONTROL devices are already configured"
- Controller Manager shows In-Port/Out-Port "None", and there is no "Traktor Kontrol S4" page in Preferences
- Preferences > Audio Setup > Phono/Line shows "Invalid"
Cause: Traktor Pro 2 talks to the S4 MK1's controls through a background service called NIHardwareService. Neither the Traktor 2.11.3 installer nor the S4 driver installer puts it on the PC. Only Controller Editor does.
Fix:
- Close Traktor.
- Open Native Access and install Controller Editor (free). I got version 2.8.2.
- Unplug the S4, wait 10 seconds, plug it back in.
- Start Traktor. The S4 lights up and Traktor adds it on its own.
How to check: open services.msc and look for NIHardwareService with status Running.
Things that did NOT help, so you can skip them: Windows 8 compatibility mode, disabling the new Windows MIDI Services, wiping the Traktor settings folder, reinstalling nothing else. Also don't add the S4 as "Generic MIDI" in Controller Manager; it belongs under Add > Traktor > Kontrol S4, and with the service running Traktor adds it automatically.
Tested on one PC only. Traktor Pro 3/4 not tested.
