There are lots of problems syncing iOS devices with iTunes 12. I’ve written about this many times, and this article has more than 160 comments, at the time of this writing, explaining the many problems that people are experiencing.

You’ll find a number of possible solutions to these issues on the web, some of which work for a handful of people. I’ve been researching this for a while, and I think I have found what is wrong, and how to fix syncing.

Two specific issues led me to my solution. The first was when I found that some of my album artwork was replaced during syncs. The artwork that was shown is not even in my iTunes library: it’s the Bob Dylan The Collection artwork you can see below, which was added to many of my Dylan albums, all purchased from the iTunes Store. (In the article linked just above, I go into great detail about the process, and about how iOS devices “phone home.”)

Similar artwork was added to my Pink Floyd albums, and some other purchased tracks.

The second was when I found that my iPhone was displaying an incorrect artist for all my Bob Dylan music: it showed “Bob Dylan & Grateful Dead” for every track by Bob Dylan, even though I don’t have that artist name in my iTunes library.

I’m pretty confident now that I have found why this is happening: it is because iOS devices contact the iTunes Store, and download some information – incorrectly, in many cases – during syncs. This explains why non-iOS devices – iPod classic, nano, or shuffle – don’t have these problems. Also, I think that the connection to the iTunes Store can be problematic, leading to syncs timing out, not completing, or taking several hours.

Some weeks ago, I had a few readers test the following procedure. Most told me that it resolved their issues, but a couple said it didn’t. I wasn’t able to find out exactly what was happening for those whose sync problems continued, so there may be other issues as well.

If you have intractable sync problems with an iOS device, you may want to try this procedure and see if it helps. Let me be very clear: I don’t think this fixes all problems syncing iOS devices with iTunes, but I believe that a large number of them are caused by iOS devices contacting the iTunes Store during the sync. Your sync issue may be different. If you’re hesitant to try this out, don’t.

WARNING: YOU MAY LOSE DATA WHEN PERFORMING THIS PROCEDURE. I TAKE NO RESPONSIBILITY FOR ANY DATA LOSS. MAKE SURE TO BACK UP YOUR ITUNES LIBRARY AND YOUR IOS DEVICE BEFORE PERFORMING THIS PROCEDURE.

THIS PROCEDURE MAY TAKE A LONG TIME. I SUGGEST THAT YOU RESTORE THE DEVICE WHICH MEANS YOU ERASE IT ENTIRELY AND LOAD A BACKUP. DO NOT START THIS PROCEDURE IF YOU DON’T HAVE PLENTY OF TIME.

IF THERE IS ANYTHING IN THE PROCEDURE BELOW THAT YOU DON’T UNDERSTAND, GO NO FURTHER.

Please follow these steps very carefully. You should be running the latest versions of iTunes 12, and iOS. You’ll need to do the syncs below via USB; wi-fi syncing won’t work.

Turn off music syncing. To do this, connect your device to iTunes, select it, and click Music in the sidebar. Uncheck Music, click Sync, and wait for iTunes to delete all your music. This may take a while if you have a lot of music. Back up your device to iTunes. To do this, select your device in iTunes, click Summary, and click Back Up Now. If you back up your device using iCloud, please go to its Settings app, then iCloud, and turn off iCloud backup. Return to iTunes and manually back up the device. Restore the device. On the Summary tab, click the Restore [device] button. After the restore procedure has completed, load the backup that you saved in step 2. Before you start syncing music, put your device in Airplane Mode. You can do this from the Settings app, or from Control Center. It’s very important that the device be in Airplane Mode until the sync has completed so it cannot make any network connections to the iTunes Store. Turn music syncing back on; check Music again, in the same place you unchecked it in step 1. Click Sync, and let iTunes sync your music. Disconnect the device, and turn Airplane Mode off.

With my iPhone, and with most of the people who tested this, syncs worked correctly. It resolved both of my issues with tags – album art and artist name – and for most of my testers, it resolved issues such as Waiting for Changes to Be Applied, and other problems.

Assuming this works correctly, you may need to put your iOS device in Airplane Mode each time you sync, at least if there’s any new content being added to the device. My main sync issues lately only affect purchased tracks – such as my Dylan, Pink Floyd, and others – and once they’ve been synced, they won’t change again. If they do change, it’s likely that the device will connect to the iTunes Store, and pull down incorrect tags again.

This is, as I say, a radical procedure, so don’t try it if you don’t understand everything you’re doing.

Please comment below if you have tried this procedure: I need to know if it works, but also if it doesn’t.