Some Apple Music Subscribers Experiencing Library Syncing Issue Across the iPhone and Mac

Over the past few months, some users have been unable to sync their Apple Music library between their iPhone and Mac, seemingly due to a bug.

iOS 17 Apple Music Feature
Affected users receive the following error message in the Music app on the Mac:

Genius results can't be updated right now. An unknown error occurred (18004).

There are complaints about the issue across the Apple Support Community, MacRumors Forums, Reddit, and elsewhere on the internet.

The underlying cause of the issue is unclear, and it's not entirely clear if a fix will require software updates, or if Apple can implement a server-side fix. We've reached out to Apple for comment, and we'll update this story if we receive a response.

This issue comes after another Apple Music bug related to playlists was fixed last month.

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Top Rated Comments

arkitect Avatar
19 months ago

Unreliable sync was the reason I gave up on Apple Music during a 90-day trial a couple of years ago. You know what service never gave me that problem? Every competitor I've ever tried (Pandora, Spotify, Deezer).
Exactly this.

I was burned by Apple Music in the transition from iTunes to Apple Music — my carefully curated music library literally — yes, literally — destroyed.

An 800GB+ music library that had been carefully sorted in albums and playlists. Mangled.
partial albums uploaded. Lossless files replaced by lossy.
Cover artwork? Pffft. Mixed and matched… missing.
Artists mixed up and ignored.

Broke my heart.

Unless there is a major rebuild from the foundations up, I will never be tempted to again.

Why other services could achieve it and the giant Apple cannot is a mystery.

And yet, how often do we hear that Apple really cares about music. "It is in our DNA" they say… yeah sure.
Score: 19 Votes (Like | Disagree)
mrmister Avatar
19 months ago

I was burned by Apple Music in the transition from iTunes to Apple Music — my carefully curated music library literally — yes, literally — destroyed.

An 800GB+ music library that had been carefully sorted in albums and playlists. Mangled.
partial albums uploaded. Lossless files replaced by lossy.
Cover artwork? Pffft. Mixed and matched… missing.
Artists mixed up and ignored.

Broke my heart.
I have never subscribed to Apple Music because of stories like this one. And syncing to my iphone has steadily become more and more of an ordeal—so much so I often just drop new material onto the phone with WALTR PRO, an app that exists to basically do what Apple can't be bothered to figure out.

Disgraceful that the people who invented the iPod can't do music and playlist transfers. This shouldn't just work—it should be seamless.

It's awful.
Score: 18 Votes (Like | Disagree)
Motawa Avatar
19 months ago
Thanks for mentioning it! Maybe Apple will now give at least just a little ****.
Score: 14 Votes (Like | Disagree)
erikkfi Avatar
19 months ago
Unreliable sync was the reason I gave up on Apple Music during a 90-day trial a couple of years ago. You know what service never gave me that problem? Every competitor I've ever tried (Pandora, Spotify, Deezer).
Score: 12 Votes (Like | Disagree)
Bustycat Avatar
19 months ago
The more Apple Music syncs, the more albums get split.
Score: 11 Votes (Like | Disagree)
vegetassj4 Avatar
19 months ago
Remember the good ole days when you would plug in your iPhone to power, and it would wirelessly wake your Mac, sync, backup, etc. with iTunes then the Mac would resume sleep?

Pepperidge Farm Remembers™

Attachment Image
Score: 7 Votes (Like | Disagree)