What does HRESULT 0x80660001 (E_AUDIO_ENGINE_NODE_NOT_FOUND) mean?

E_AUDIO_ENGINE_NODE_NOT_FOUND

E_AUDIO_ENGINE_NODE_NOT_FOUND belongs to PortCls audio-engine node discovery. A miniport claimed IMiniportAudioEngineNode support but PortCls could not locate the corresponding audio-engine node in its topology.

Start with the returning API

An audio miniport that exposes the audio-engine interface must make its topology descriptor and node identifiers agree with that claim. PortCls cannot infer a missing engine node from friendly endpoint names. The node table, KS topology, miniport interfaces, and subdevice on which the interface is exposed must all describe the same logical engine.

the interface claim and the KS topology must describe the same node. A missing node can result from a wrong node ID, inconsistent descriptor tables, exposing the interface on the wrong subdevice, or failing to create the topology expected by PortCls.

Evidence to preserve

• Adapter and subdevice instance IDs
• Miniport interface query result and audio-engine node ID
• KS filter node descriptors and automation tables
• PortCls trace and the call that first asks for the engine node

Reproduce without destructive cleanup

Compare the descriptor tables used at registration with the node ID returned by the miniport. A minimal SysVAD-derived topology is a better control than an unrelated working USB or Bluetooth endpoint because those devices use different driver and topology paths.

1. Compare the node ID returned by the miniport with the published topology descriptors.
2. Run the same topology through the SysVAD sample structure as a control.
3. Verify WaveRT and topology subdevices are paired as intended.
4. Check build-time descriptor counts and conditional feature flags.

Limits of this code

This differs from E_HDAUDIO_NO_LOGICAL_DEVICES_CREATED: the current failure is a specific PortCls engine-node contract, not total failure to create codec subdevices. Do not remove IMiniportAudioEngineNode support merely to suppress the status if the driver still depends on engine-node properties.

Technical references

• Microsoft: COM error codes for Input and graphics.
• Microsoft: PortCls interfaces and structures.
• Microsoft: Windows audio driver design guide.
• Microsoft: hdaudio.h header reference.
• Microsoft: SysVAD virtual audio driver sample.