The categories are deliberately broad
MDN documents aborted, network, decode and unsupported-source categories. An aborted operation can reflect interruption; a network category concerns retrieval; decoding concerns processing received media; unsupported source concerns a source the browser cannot use. Keep the reported category rather than translating every failure into buffering.
For an illustrative example, an unsupported source before the first frame and a decode failure forty minutes into a film need different evidence. The former points toward source selection and support checks. The latter benefits from the content position and whether the same boundary fails again under comparable conditions.
Separate an error from surrounding observations
A request trace may show successful delivery of a playlist followed by failure of a nested segment. Another trace may contain successful transfers and a subsequent decode error. A screenshot of the initial 200 response cannot distinguish these runs because it captures only one earlier stage.
Record the player message verbatim when possible, the browser version, whether audio or video started and the approximate content position. Avoid pasting private signed addresses into public reports. The useful part is the relationship between the failure and the required resource, not disclosure of the account-bearing URL.
Use a narrow comparison
A second supported browser or a different authorised representation can help isolate the issue if available. Keep the programme and observation window comparable. If one test uses a low-resolution on-demand clip and the other a live high-rate presentation, their different outcomes do not isolate a browser decoder.
A code is also not a permanent compatibility verdict. Software versions, media configuration and delivery responses can change. Escalate with the actual category and context; do not claim a codec, a server outage or an expired subscription unless an additional observation or official requirement supports that conclusion. Preserve successful stages as evidence too.
Questions about this guide
Does a network media error prove my broadband is down?
No. It identifies a broad retrieval failure; the failing request and path still need investigation.
Does a decode error identify one exact codec problem?
No. The category needs media and implementation context.