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NS_E_WMPCORE_CODEC_NOT_TRUSTED
Diagnosing NS_E_WMPCORE_CODEC_NOT_TRUSTED
Windows Media Player reports this result (0xC00D109A) when the candidate codec fails the trust/signature policy required for installation/use. The playback core codec not trusted condition is owned by the core that resolves Player.URL, selects or builds a playback graph, chooses codecs and devices, prerolls media and advances between playlist items while reporting asynchronous errors.
Evidence that separates the result
| Field | What to record |
|---|---|
| Decisive check | Record codec CLSID, package/signature chain and source |
| Artifact identity | Player.URL, current media sourceURL and resolved final URL for this reproduction |
| Runtime state | Play state and transition immediately before failure for this reproduction |
| Owning object | Selected graph/source/filter or codec identity and version for this reproduction |
| Lower-level result | Audio/video device identity and driver generation for this reproduction |
| Correlation | Ordered ErrorItem queue with errorCode, errorContext and media object for this reproduction |
Representative case: Automatic codec discovery retrieves an unsigned or altered installer. The example isolates only the producing component.
Nearby results with different boundaries
| Result | Different boundary |
|---|---|
NS_E_WMPCORE_CODEC_NOT_FOUND | The graph cannot find the specific codec required for a media stream |
NS_E_WMPCORE_MISNAMED_FILE | The file extension/name disagrees with the content or supported media interpretation |
NS_E_WMPCORE_CODEC_DOWNLOAD_NOT_ALLOWED | The required codec is absent and Player policy/settings prohibit automatic acquisition |
Verification
Repeat the original operation with a fresh owning object after the identified precondition is corrected. Treat this result as resolved only when that same operation passes this stage; preserve any later HRESULT as a separate failure.
Technical references
- Windows Media Player SDK — documentation used to identify the producing boundary of this result.
- Player MediaError event — normative or platform material relevant to it.
- ErrorItem object — API or format context for this HRESULT.
- Supported protocols and file types It.
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