Recent Windows 11 updates (Feb/March 2026) introduce native Windows MIDI Services, which may conflict with virtual ports tools like loopMIDI, causing ports to disappear. The following workaround can be used to circumvent the issue while waiting for a proper fix in a future Windows 11 update.
Service Restart Fix: If loopMIDI stops working, restart the Windows MIDI Service:
- Press Win + R, type services.msc, and press Enter.
- Locate Windows MIDI Service (or MIDI Services).
- Right-click → Stop, then Start.
- Restart your MIDI application afterward.