Error occurs when trying to sync Apple Music library between iPhone and Mac

Try rebooting your Mac. Mine started working again as soon as I rebooted.

All seems back to normal now and my extensive Playlist and curated Music returned as I had it.

Good luck!

My advise is to not change any settings on your iPhone related to the Music app. There is a good chance that you will experience the same issues on your phone if you stop syncing. Do you have another apple device? If so you can try to add a song to a playlist and check if it syncs across your devices (except your Mac of course).

Same problem - it takes forever to load cloud music library, music, playlists and other data from Apple music not accessible at all. Newly music added on my mac not showing on other devices. It has something to do this Genius data communication with apple servers. I tried tuning off Genius with no success - it keeps turning on.

If you want to transfer local music to devices you have to disable Sync library than manually sync via Finder and then re-enable Sync library and merge the libraries.

I use the iCloud music library a lot and have more than 200 albums on my mac and I'm adding more from time to time. No solution written here works now. I hope Apple provide an easy fix soon.

Same issue here. Called up apple support they told me the apple engineers are aware of the issue and I'll have to wait for a fix in the form of an update. Anyone had any lucky resolving it on their own as both my Mac and iPhone music apps are completely broken.

Adding my name to the list as well. Have been experiencing this occasionally on single devices since October. Then turning on/off iCloud sync fixed it temporarily. Been talking to Apple support several times during these months but no luck. Just the same story that their engineers are working on the problem and let's wait for an update. Now after the latest update 14.2.1 all my devices have the same issue. Apple Music replication of music library across devices are completely broken. Signing in and out that support suggested wiped all playlists from my Iphone and one of my MacBooks. So beware!

Let's really hope they are taking this issue seriously.

Hello everyone,

I have been facing this issue since yesterday morning. I initially encountered this problem at the end of October (on Sonoma), and the only way to work around it with the help of Apple support was to format my Mac and revert to Ventura using a backup. I stayed on Ventura for three weeks before switching back to Sonoma because there was an update. I thought they had probably fixed this bug. It worked until yesterday when this message error came again .. I tried to signed out and signed back in on my MacBook Pro, my iPhone and iPad to try to resolve the sync issue. Now, I no longer have my library on my MacBook Pro, iPhone, or iPad. This afternoon, I sought help from Apple support, reverted again to Ventura, but nothing has changed. I still encounter the error message 18004. I wonder if the problem might be related to iOS updates rather than Sonoma, as it persists even on Ventura.

Could be, but I doubt it. I experienced no issues under Ventura, while consistently updating iOS at every occasion (per my company’s policy). I even had no issues under Sonoma, until I updated to 14.2.1 earlier this week. So to me it’s clear the issue is with 14.2.1.

Apple Music on my Mac wouldn't let me add any music to my library so I signed in and out, and I got this exact error. I tried signing out again as well as reseting my Icloud password which hasn't worked. Now Apple Music on my Iphone does not sync either even after signing out and in again with the new password. Apple Music only syncs on the web app on a browser, the rest is completely dysfunctional.

I have the same issue .. M1 Mac mini Sonoma 14.2.1 .. I've tried the usual stuff (sign-out iCloud, sign-out Music account, turn off-on library sync, another wifi connection) .. Web Player is completely fine ..

I'm having the exact same issue as you, unfortunately, on my iPhone 15 Plus. On the web version and Xbox version everything is working fine its just my iPhone and the Apple Music app on Windows 11. I contacted apple support yesterday via text and they failed to assist me so they provided a callback for today, after being left on hold by multiple "senior advisors" for 2 hours, one finally decided to assist me. That advisor provided no help at all and only recommended me to purchase iCloud storage?? I did do that though after the call had ended and it still fixed nothing. This is the most frustrating bug I've ever been through; I add music to playlists and download them, but then poof! all songs have mysteriously disappeared and deleted themselves. I've tried restarting and everything, including unsyncing library then resyncing library, nothing works at all. Please, if anyone finds a fix, let me know

Just checked and it has now synced my whole library and playlists to the app on Mac OSX ... I am in Australia if that helps!

Didn't do anything special - just reopened the Music app on my iMac. Fingers crossed it stays fixed!

It seems like it two types of errors involved in the discussion. The Apple Music IOS sync that stopped working about two weeks ago on IOS devices.  Then we have the 18004 error on OSX devices that has been around since many months. I started experience that in October. 

The old problem appeared occasionally and before the latest problems it was sometimes fixed when signing in/out / turning sync on/off. But since mid December the sync on OSX devices stopped working completely together  with the IOS devices and when following apple support instructions signing in and out it wiped the whole library. Like many of us have experienced.  

Now it looks like that ”bigger” issue works again. But the old error 18004 still is there. Any way for me. But this time it won’t help signing in/out, switching sync on/off. 

So Apple. Please give us something to hope for when this issue is going to be fixed. It’s annoying and very troublesome that nothing seems to be done.  Ive been told twice now the last months during calls to support to wait for update. And every update has only made the problem worse. 

We trust you with our data and it’s a big worry what’s really happening. 

Is it a minor problem to you and its therefore the fix its delayed for months?

Is it a security breach or another major issue that you really don’t know how to resolve?

What’s happening?

No, you can see that your library is ok if you use the web version of apple music(https://music.apple.com/ru/browse). they have problems with synchronization.

I don't think thats likely. Because Apple Music is also not working on previous versions of IOS and MacOS. So it is not a client side fix, they need to fix something on the server side.

It’s a bug on their side(OS/Server Side). Because you can find all of your songs in https://music.apple.com/ru/browse

And this is really “funny”…