I'm also getting this error:
{
"errors": [
{
"id": "KX7SPPFCOEATR42NHSDWMRAHT4",
"title": "Upstream Service Error",
"detail": "Service failure: Cloud Library",
"status": "500",
"code": "50001"
}
]
}
It happens when I save a playlist to the POST https://api.music.apple.com/v1/me/library/playlists endpoint. The playlist seems to save fine to my library, so it seems odd that I'm getting this error.