fetchTranscript fails when playerCaptionsTracklistRenderer is missing

[wilonweb]

Description

When using YoutubeTranscript.fetchTranscript(videoId), the method throws the following error on some videos:

Cannot read properties of undefined (reading 'playerCaptionsTracklistRenderer')

This happens consistently for certain videos, even on the latest version of the library.

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Example video

https://www.youtube.com/watch?v=I7_WXKhyGms

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Minimal reproduction code

const { YoutubeTranscript } = require("youtube-transcript");

(async () => {
  try {
    const transcript = await YoutubeTranscript.fetchTranscript("I7_WXKhyGms");
    console.log(transcript);
  } catch (err) {
    console.error(err);
  }
})();

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Error output

Cannot read properties of undefined (reading 'playerCaptionsTracklistRenderer')

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Expected behavior

Instead of throwing a low-level parsing error, the library should:

• Return an empty array, or
• Throw a clear error such as No captions available for this video

when captions are unavailable or the YouTube response structure is different.

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Context / hypothesis

It seems that playerCaptionsTracklistRenderer is missing from the YouTube player response in some cases, for example:

• videos without captions
• restricted or age-gated videos
• region-restricted videos
• or when YouTube changes its internal response structure

A defensive check before accessing playerCaptionsTracklistRenderer would prevent this crash.

::contentReference[oaicite:0]{index=0}

[alucarded]

It seems YouTube no longer provides captions via InnerTube API. I hope I am wrong, but I cannot get captions for any video recently.