Error: The RSS file isn’t working

We tried to get the RSS file for this podcast - https://ssi.armywarcollege.edu/media/Audio/SSI-Live/SSI-Live.xml - but it wouldn’t load for us.

array (
  'wrapperType' => 'track',
  'kind' => 'podcast',
  'collectionId' => 893988551,
  'trackId' => 893988551,
  'artistName' => 'Unknown',
  'collectionName' => 'SSI Live',
  'trackName' => 'SSI Live',
  'collectionCensoredName' => 'SSI Live',
  'trackCensoredName' => 'SSI Live',
  'collectionViewUrl' => 'https://podcasts.apple.com/us/podcast/ssi-live/id893988551?uo=4',
  'feedUrl' => 'https://ssi.armywarcollege.edu/media/Audio/SSI-Live/SSI-Live.xml',
  'trackViewUrl' => 'https://podcasts.apple.com/us/podcast/ssi-live/id893988551?uo=4',
  'artworkUrl30' => 'https://is4-ssl.mzstatic.com/image/thumb/Podcasts/v4/47/92/2e/47922e09-a1cb-673c-9778-c72a68f21a27/mza_216081224832084289.jpg/30x30bb.jpg',
  'artworkUrl60' => 'https://is4-ssl.mzstatic.com/image/thumb/Podcasts/v4/47/92/2e/47922e09-a1cb-673c-9778-c72a68f21a27/mza_216081224832084289.jpg/60x60bb.jpg',
  'artworkUrl100' => 'https://is4-ssl.mzstatic.com/image/thumb/Podcasts/v4/47/92/2e/47922e09-a1cb-673c-9778-c72a68f21a27/mza_216081224832084289.jpg/100x100bb.jpg',
  'collectionPrice' => 0.0,
  'trackPrice' => 0.0,
  'trackRentalPrice' => 0,
  'collectionHdPrice' => 0,
  'trackHdPrice' => 0,
  'trackHdRentalPrice' => 0,
  'releaseDate' => '2018-07-31T08:35:00Z',
  'collectionExplicitness' => 'notExplicit',
  'trackExplicitness' => 'notExplicit',
  'trackCount' => 80,
  'country' => 'USA',
  'currency' => 'USD',
  'primaryGenreName' => 'News',
  'artworkUrl600' => 'https://is4-ssl.mzstatic.com/image/thumb/Podcasts/v4/47/92/2e/47922e09-a1cb-673c-9778-c72a68f21a27/mza_216081224832084289.jpg/600x600bb.jpg',
  'genreIds' => 
  array (
    0 => '1489',
    1 => '26',
  ),
  'genres' => 
  array (
    0 => 'News',
    1 => 'Podcasts',
  ),
)...https://itunes.apple.com/lookup?id=893988551

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