What does HRESULT 0x80EE0024 (RTC_E_MEDIA_AEC) mean?

RTC_E_MEDIA_AEC

What RTC_E_MEDIA_AEC means in RTC

This result belongs to the RTC media controller and terminal boundary area of RTC and identifies RTC failed to enable acoustic echo cancellation for the audio path.

This result carries 0x80EE0024 in the RTC interface facility 0xEE; store the result value at the first RTC callback or method boundary, before retry logic replaces it with a broader timeout or connection message.

Collect enough state to record capture/render pairing, device formats, audio topology, and whether AEC was mandatory; the result evidence should demonstrate why AEC failure is an audio-processing capability issue and need not mean basic audio cannot run.

Protocol and object state

Signaling success does not guarantee that a capture or render device exists or that a media stream can start. AddStream, RemoveStream, hold, and terminal selection change the media state machine and can race with callbacks from the previous operation.

How to prove the condition

1. Use protocol and object evidence to record capture/render pairing, device formats, audio topology, and whether AEC was mandatory.
2. Confirm the distinction that AEC failure is an audio-processing capability issue and need not mean basic audio cannot run.
3. Start a fresh operation after you fall back only when product policy permits, or choose an AEC-compatible device path, and compare its final state with the failing run.

The result diagnosis is strongest when object state and protocol trace share timestamps and transaction identifiers; when diagnosing this result, avoid treating packet capture and HRESULT logging as substitutes for one another.

Minimum incident record

• Code-specific proof: record capture/render pairing, device formats, audio topology, and whether AEC was mandatory.
• Owning object: stream direction and negotiated codec.
• Wire evidence: device removal or format-change event.
• Lifecycle state: session and media type.

Actions that do not address this condition

• Do not recreate the entire SIP session before determining whether only a local terminal failed.
• Do not assume the default Windows device is the terminal selected by the RTC object.

Correct application response

The owning RTC component should fall back only when product policy permits, or choose an AEC-compatible device path; it should also settle or cancel its previous operation before callers begin a replacement.

Example: A split capture/render device combination does not support the RTC echo-cancellation topology.

Nearby failure modes

Technical references

• About the RTC Client API.
• Creating an RTC session.
• Microsoft RTC return constants.
• SDP offer/answer.