Apple Watch Cellular Setup Failed? How To Fix “Couldn’t Sync iCloud Data” Error

For the last few days, I’ve been trying to get my new Apple Watch Cellular to sync with my iPhone, but I keep hitting the same roadblock. A pop-up saying “Couldn’t sync iCloud data” appears during the setup process. I can either cancel or delete the data, but the latter does nothing. The Watch app just keeps showing a server error. After some research, I found a few troubleshooting steps that target the most likely causes. If you’re facing the same issue, here’s everything you should know.

How To Fix Couldn’t Sync iCloud Data Error

I’ve organized the troubleshooting steps by difficulty. Start with the simplest to fix the issue with minimal effort.

1. Sign Out and Sign In Again to iCloud

NOTE

If you recently updated to the latest iOS, you might face a security delay of 1 hour or more to sign out and sign in to iCloud.

2. Enable iCloud Passwords & Keychain

Enabling iCloud Passwords & Keychain syncs your saved passwords, Wi-Fi credentials, and authentication data across your Apple ecosystem. This allows seamless pairing and automatic access to encrypted services.

1. Open the iOS Settings app and tap on your Apple ID or avatar on the top.
2. You’ll enter Apple Account settings.
3. Find and tap on the iCloud settings menu.
4. Inside iCloud, tap on the Passwords card to access the Passwords & Keychain menu.
   
5. There, toggle on the Sync this iPhone feature.
   

Sometimes, you might find that the Passwords & Keychain sync is already active and you’re still getting the Couldn’t Sync iCloud Data error. In that scenario, simply toggle off and on Sync this iPhone in the Passwords & Keychain menu.

3. Setup Passcode on iPhone

If the passcode feature is disabled on your iPhone, I strongly suggest turning it on. A quick reset should clear minor bugs in your pairing connection, and it’s also your first line of defense against thieves.

1. Navigate to the Settings app and tap Face ID & Passcode (or Touch ID & Passcode on earlier models).
2. Tap Turn Passcode On and enter a six-digit passcode.

4. Disable and Enable Advanced Data Protection

1. Open the Settings app, scroll up to the Apple Account section, and tap on your avatar.
2. In the Apple Account window, find and tap on the iCloud option.
3. Scroll down to the bottom of the iCloud window and tap on the Advanced Data Protection option.
4. Tap Turn Off Advanced Data Protection and follow the on-screen prompts to disable the feature.
5. Reboot your iPhone.
6. Now, follow the same steps as listed above to reach the Advanced Data Protection screen.
   
7. Tap on the Turn On Advanced Data Protection button.
   
8. The Set Up Account Recovery pop-up will show up.
   
9. Tap on that and follow the on-screen instructions to complete the setup process for the Advanced Data Protection feature.

5. Apply iOS and watchOS Updates

For iOS Update

1. On your iPhone, go to the Settings app and tap on General.
2. Select the Software Update option in the General window.
3. If an update is available, tap the Download and Install or the Update Now button.
   
4. Follow the on-screen prompts to complete the device update process.

For watchOS Update

1. Launch the Watch app on your iPhone.
2. Go to the My Watch tab by selecting the same at the bottom left corner of the app window.
3. Now, tap on the General option in the My Watch tab.
   
4. Inside the General window, find and tap on the Software Update option.
5. Tap Agree for all the terms and conditions pop-ups.
6. If the download is ready for installation, you’ll only see the Install button. Tap Install.
   
7. Sometimes, the Install button might be replaced with Download and Install when the iPhone needs to download the necessary files.
8. Enter the iPhone passcode to authenticate.
9. The iPhone will update the Apple Watch remotely and a progress wheel will appear on the Watch Face.

Contact Apple Support if issues persist. You can also read about possibly correlated problems, like if the pairing connection between your Apple Watch and iPhone isn’t pushing through.