Issues with iPhone sync from MacBook after iOS17 **Apple watchOS 10 to Blame**

I can confirm that the problem persists under iOS 17.2 (iPhone 14 Pro Max) on macOS Ventura 13.6.3, with Apple Watch Series 6 updated to watchOS 10.2.

My iOS backups are performed locally (via USB cable) and started noticing the neverending "Preparing to sync..." (Step 3) tonight. Once unpairing my watch from within the iOS Watch app (while the iPhone was still connected and caught in this loop), the minute that the device recognized that the Watch was no longer associated with the iPhone, the sync completed normally.

I was constantly killing the MDCrashReportTool process just to get out of the sync hang, but the hang would return the next time the iPhone was connected. (the process starts itself up evidently at each connection to the iMac)

I just repaired the watch to the iPhone (albeit using the last watchOS backup found) - hoping that the fresh pairing completes the sync process. I just pressed "Sync" from the iPhone's Finder window (while iPhone still connected) and the sync performed as expected.

The real test is when reconnecting the iPhone to the iMac for the next backup and sync... (I'm a little fried at the moment, and don't have the patience to go through the unpairing steps again, just in case)

Regardless, you definitely get the upvote for detecting this! If you haven't submitted a bug report feedback submission as of yet (via https://www.apple.com/feedback/) I highly suggest you do so.

I have had the same sync problem with my macOS 14.2 and iOS 17.2 when I was trying by USB-C. 

My solution was abort synching by pull of the cable, insert again and the first thing I checked in the sync settings was "show this iPhone when on Wi-Fi". After this my syncing works correct. With or without cable.

See also here (in german, sorry): Synchronisieren von Inhalten zwischen deinem Mac und dem iPhone, iPad oder iPod touch über WLAN - Apple Support (DE)

Info: My Apple Watch series 4 (watchOS 10.2) was still paired on iPhone!

Hope that helps 😉 

Best, Tom

Hello Dennis. Steve A's solution to force quit the process "MDCrashReportTool" in Activity Monitor on the Mac is working for me. I've been able to sync music by doing this.

Basic steps: Start sync. When the sync reaches step 2 "preparing sync", look for the "MDCrashReportTool" in Activity Monitor. Double click it, and choose force quit. Then sync will complete.

Bad news. For me, each time I start a sync, I have to repeat the above steps. It has become a muscle memory step for me though. If you need any other help with this, let me know (I might have left out a step).

I am having the exact same issue. So glad I happened to stumble upon your post about it. In my case the process would either get stuck at "Preparing to Sync" or would immediately start "Canceling Sync" as soon as iPhone was plugged in to MacBook. After unpairing the watch and restarting my phone, sync worked no problem. In my case the devices are:

-iPhone 12 Pro (iOS 17.1.1)

-MacBook Air 2013 (Monterey, Version 12.7.1)

-Apple Watch SE (WatchOS 10.1.1

And I can triple confirm this. The "preparing to sync" stage was taking a little longer than I hoped, but the sync did continue and complete. I did a second sync, and this was much quicker (which is something I remember from before, if I left my iPhone attached to my Mac, the subsequent syncs were finished quickly).

And I just completed updating my Mac, iPhone and Apple Watch to their .3 operating systems.

Looks like we are finally a go. Thanks all!

Steve A. wrote:

I can confirm that the problem persists under iOS 17.2 (iPhone 14 Pro Max) on macOS Ventura 13.6.3, with Apple Watch Series 6 updated to watchOS 10.2.

The real test is when reconnecting the iPhone to the iMac for the next backup and sync...

Update - the sync process is still broken when the iPhone is reconnected having an active Apple Watch pairing in place with the watch powered on:

Resetting the Apple Watch sync data (from Watch app: Settings > General > Reset > Reset Sync Data) while iPhone is connected has no effect. The process will only complete once the watch pairing has been removed.

I can say with certainty that iOS 17.1.2 and watchOS 10.1 (or was it 10.1.1) did not have this issue - manual sync was fine. So it's a fair statement that with one of those OS's recent changes, something broke with the sync process.

wstuart66 wrote:

Thanks to all for replying and letting me know I am not the only one!

For what it's worth, the problem persists in macOS Sonoma 14.2, iOS 17.2, and watchOS 10.2.

I have submitted more than one report to Apple regarding this.

The ONLY time the iPhone will sync normally with the Mac is if the watch is NOT paired with the iPhone.

At this time I have un-paired my watch and I am not using the Apple Watch due to this issue.

The other short-term fix I was able to pull out from other forums (and evidently, sync issues such as this did occur in the past with other iOS versions) was to force-quit the process "MDCrashReportTool" - on macOS, this can be done through Activity Monitor (Applications > Utilities). This at least will get the sync process to the tail end (i.e. sync of Contacts and Calendars) to completion. But if you choose to keep the Apple Watch paired (as I am so stubbornly doing), this is the only way to complete the sync. This process starts again each time the iPhone is connected to macOS, so it's probably best to unplug/re-plug if you have to attempt another sync via this method.

Luckily though, even by killing this process I can still manually add media to the iPhone - Music still recognizes that it's connected.

Between this and album purchases splitting randomly into multiples, iOS 17.1 / 17.2 is becoming a bug infestation...

Just added my Apple Watch back to my iPhone 13 Pro on iOS 17.3 (went live Jan 22nd) and it looks like this issue has been resolved, thank god! I can go back and use my Apple Watch once again! No more hanging sync issues!

I don't know what other equipment you are on, but the sync is now working with the new os updates that came through yesterday. Here's my system:

Macbook Pro: Sonoma 14.3

iPhone 14 Pro Max: iOS 17.3

Apple Watch 9: 10.3

Be prepared, the step "Preparing to sync" may take a few minutes (almost 6) the first sync, but subsequent syncs should go much quicker.

If you cannot update your system to the newest operating systems, the workarounds using Activity Monitor & to Force Quit the process "MDCrashReportTool", should get your syncs to complete.

Good luck!

rbd

I simply turn off my watch prior to syncing phone to MBP.

Prior to that I was killing the MDCrashReportTool.exe but noticed while it would stop the “hang” at step 3 not all would sync.

I had tried this a month or two prior and it still wouldn’t sync. So recent update did change that.

Another thread addressing same issue with folks using the usb connection (I found it didn’t matter wifi or usb reacted same).

https://discussions.apple.com/thread/255265364?login=true&sortBy=best

I just tried my first sync with Steve A's plan to force-quit the process "MDCrashReportTool" - on macOS. I can confirm that this works, at least with my hardware configuration. I was finally able to complete a sync. At least I have (what appears to be) a workable solution until Apple fixes this. Thanks to all, and if I run across any other ideas, I'll make sure to post them here.

Thank you Steve A., that worked for me too (iPhone 13 on 17.2.1, Watch on 10.2 and connected, and iMac on Sonoma 14.2.1). But fyi I was also able to sync over wifi without the need to Force Quit the MDCrashReportTool.

Nick

Force quitting the MDCrashReportTool is the only way I know to continue the sync process. Until that is done, the process just sits during step 2. As soon as the process is killed everything speedily proceeds.

Apple really needs to fix this issue. It's been open a long time and it seems that many users are going through crazy steps for what is otherwise a simple, yet import process.

Thank you all for isolating the issue and providing evidence it wasn't just an issue I was experiencing! Confirming that this began happening to me mid-December 2023 on my machine which runs Monterey 12.7.2. I reset the phone and thought that would fix it, but no. I unpaired my Apple Watch today and immediately the syncing process completed. Hoping for a fix ASAP on the next iOS/watchOS update.