Audio Features endpoint returns HTTP 500 for some tracks

[johnreutersward]

Getting audio features for certain tracks yields a HTTP 500 with an empty body.

Normally, when an ID is invalid or missing a null value is returned in its place.

Input:

7ouMYWpwJ422jRcDASZB7P,invalidId

Response: 

{
  "audio_features": [
    {
      "danceability": 0.366,
      "energy": 0.963,
      ...
    },
    null
  ]
} 

For some values the whole request fails with HTTP 500 and the response body is empty.

Two examples I have found that can be tried in the console https://developer.spotify.com/console/get-audio-features-several-tracks

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