Sync Services: Advanced troubleshooting for contact and calendar syncing

Learn how to correct issues involving syncing contacts, contact groups, or calendar events with your Mac or with third-party mobile devices and applications connected using USB.

Before You Begin

The steps in this article only apply if:

Important: Before performing any of the steps in this article, you should back up your data.

Solving Sync-related issues

Issues syncing contacts and contact groups

Back up your contacts

  1. Open Contacts.
  2. Back up your contacts by choosing File > Export and selecting Contacts Archive. Specify an export location and then click Save. The resulting archive file contains a backup of all of your contact information that you can restore later into Contacts if needed, by double-clicking the backup file in the Finder.

Fix the issue

  1. Remove any duplicate or unnecessary blank entries. Select an account from the Groups sidebar. If you don’t see the sidebar, choose View > Groups. Choose Card > “Look for Duplicates.” Click Merge. Contacts creates a single card for each contact using the name and picture of the card that was listed first. It may be necessary to repeat this procedure until duplicate entries no longer appear.
  2. Choose Contacts > Preferences, then click the vCard tab. Ensure the 3.0 option is selected for vCard Format and that both the “Export notes in vCards” and “Export photos in vCards” options are selected.
  3. Create a new folder on the desktop.
  4. Select all of the contacts in the Name category in Contacts by choosing one of them, and then choosing Edit > Select All.
  5. Drag all these contacts into the new folder on the desktop by clicking and dragging one of the highlighted names; this results in a single vCard file that contains all of your contacts.
  6. If you have contact groups in your Contacts, select and drag each group to the new folder on the desktop (a vCard is generated for each group).
  7. Disable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later.

    1. In the Finder, choose Go > Utilities.
    2. Open Terminal and execute this command:

       

      defaults -currentHost write com.apple.syncservices SyncingDisabled YES

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Disable the option to "Enable syncing on this computer."
  8. Delete all of the contacts and groups in Contacts.
  9. Quit Contacts.
  10. Hold the Option key while clicking the Go menu in the Finder in order to select the Library folder (if you are using Mac OS X v10.6 or earlier, choose Go > Home in the Finder, then open the Library folder), and then open the Application Support folder.
  11. Locate the "Address Book" folder and move it to the Trash.
  12. Hold the Option key while clicking the Go menu in the Finder in order to select the Library folder (if you are using Mac OS X v10.6 or earlier, choose Go > Home in the Finder, then open the Library folder).
  13. Open the Preferences folder in the Library folder.
  14. Move the following files to the Trash:
    • com.apple.AddressBook.plist
    • com.apple.AddressBook.abd.plist
  15. Hold the Option key while clicking the Go menu in the Finder in order to select the Library folder (if you are using Mac OS X v10.6 or earlier, choose Go > Home in the Finder, then open the Library folder).
  16. Drag the files located inside the "Caches" folder to the Trash (do not move the "Caches" folder itself, only its contents).
  17. Choose Go > Go To Folder from the Finder, then go to this location: /Library/Caches
  18. Drag the files located inside the "Caches" folder to the Trash (do not move the "Caches" folder itself, only its contents).
  19. Choose Log Out from the Apple menu to log out of your user account.
  20. Once logout is complete, log back into your user account.
  21. Reset the SyncServices folder using the appropriate method for your operating system.

    OS X Mavericks 10.9.3 or later

    1. In Terminal, type or paste the following command on a single line:

       

      defaults delete com.apple.SyncServer SyncServicesResetWorldRunOnce

       

    2. Restart your computer
    OS X Lion and OS X Mountain Lion
    1. In the Terminal window, type or paste the following command on a single line:

       

      /System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl full

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Choose iSync > Preferences > Advanced > Reset Sync History.
  22. Re-enable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later

    1. In the Finder, choose Go > Utilities.
    2. Open Terminal and execute this command:

       

      defaults -currentHost delete com.apple.syncservices SyncingDisabled

       

    Mac OS X Snow Leopard and Mac OS X  Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Enable the option to "Enable syncing on this computer."
  23. Open Contacts.
  24. Drag the vCard from the folder you created on your desktop to the Contacts window to re-import them. To re-create contact groups, create the groups first in Contacts and then drag the appropriate vCards to each group.
  25. Attempt to sync normally using iTunes for your iPhone, iPad, iPod, and iPod touch, or use iSync for other mobile devices.
  26. If the contacts still do not sync, try starting your computer in Safe Mode by pressing and holding down the Shift key after hearing the chime on startup. It may take several minutes to start your computer in Safe Mode. After starting in Safe Mode, restart your computer and then attempt to sync normally.
  27. If your contacts don't sync, consider contacting AppleCare for support.
  28. Once your contacts and groups sync correctly, create a new backup of your contacts, using the procedure outlined in step 1. This preserves any of the changes you made that fixed your sync issue.

Issues syncing calendars

Back up your calendar data

To back up your appointments:

  • Choose File > Export > Calendar Archive in OS X Mountain Lion or later
  • Choose File > Export > iCal Archive in OS X Lion or Snow Leopard.
  • Choose File > Back up iCal in OS X Leopard

Fix the issue

  1. Quit Calendar.
  2. Disable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later

    1. Open Terminal and execute this command:

       

      defaults -currentHost write com.apple.syncservices SyncingDisabled YES

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Disable the option to "Enable syncing on this computer."
  3. Hold the Option key while clicking the Go menu in the Finder in order to select the Library folder (if you are using Mac OS X v10.6 or earlier, choose Go > Home in the Finder, then open the Library folder).

  4. Open the Calendars folder. 
  5. In the Finder, delete the Calendar Cache files, including any that also display a -1 (or -2, -3, and so forth) directly after their filename.
  6. Choose Go > Go To Folder in the Finder, then go to this location:  /Library/Caches
  7. Drag the files located inside the "Caches" folder to the Trash (do not move the "Caches" folder itself, only its contents).
  8. Reset the SyncServices folder using the appropriate method for your operating system.

    OS X Mavericks 10.9.3 or later

    1. In the Terminal window, type or paste the following command on a single line:

       

      defaults delete com.apple.SyncServer SyncServicesResetWorldRunOnce

       

    2. Restart the computer
    OS X Lion and OS X Mountain Lion
    1. Choose Go > Utilities in the Finder.
    2. Open Terminal and type or paste the following command on a single line:

       

      /System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl full

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Choose iSync > Preferences > Advanced > Reset Sync History.
  9. Re-enable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later

    1. Open Terminal and execute this command:

       

      defaults -currentHost delete com.apple.syncservices SyncingDisabled

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Enable the option to "Enable syncing on this computer."
  10. Open Calendar.
  11. Attempt to sync normally using iTunes for your iPhone, iPad, iPod, or iPod Touch, or use iSync for other mobile devices. If the sync does not work, attempt to sync only one calendar at a time, noting which calendars do not sync.

If the issue continues and is isolated to specific calendars, there may be an issue with an event title. Check your event titles for the following:

  • Check to see if any calendar events have blank or empty titles. If so, rename these events so they have a title or delete the event.
  • Check for calendar entries containing any events using high ASCII or double-byte (Unicode) characters in the event title (such as Japanese, Chinese, Korean or other extended ASCII characters). Try removing these characters or substituting them with non-extended ASCII characters.
  • Check for and remove any duplicate calendar entries.
  • Consider removing some old events if you have a very large number of them.

OS X Mountain Lion and later

  1. Open Calendar.
  2. Type a period in the Search field located in the top right corner.
  3. All of your calendar events appear in the search results. Depending on how many events you have, it may take a few minutes for all of them to display.

OS X Lion, Mac OS X Snow Leopard, or Mac OS X Leopard

  1. Open iCal.
  2. Type a period in the Search field located in the top right corner.
  3. All of your calendar events appear in the search results, located in the bottom of the window. Depending on how many events you have, it may take a few minutes for all of them to display.
  4. Click the Title field in the search results to sort by title, as shown below:

Mac OS X v10.4 or earlier

  1. Open iCal.
  2. Click the list button in the lower right corner of the iCal window.
  3. Click the Title field in the results list to sort by title.

If you are unable to resolve your issue by locating and renaming potentially problematic event titles, continue troubleshooting with these steps:

  1. Disable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later

    1. Open Terminal and execute this command:

       

      defaults -currentHost write com.apple.syncservices SyncingDisabled YES

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Deselect the option to "Enable syncing on this computer."
  2. Remove all the calendars in iCal.
  3. Reset the SyncServices folder using the appropriate method for your operating system.

    OS X Mavericks 10.9.3 or later

    1. In the Terminal window, type or paste the following command on a single line:

       

      defaults delete com.apple.SyncServer SyncServicesReset

       

    2. Restart the computer.
    OS X Lion and OS X Mountain Lion
    1. In the Finder, choose Go > Utilities.
    2. Open Terminal and type or paste the following command on a single line:

       

      /System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl full

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Choose iSync > Preferences > Advanced > Reset Sync History.
  4. Re-enable syncing using the appropriate method for your operating system.

    OS X Lion, OS X Mountain Lion, and Mavericks 10.9.3 or later

    1. Open Terminal and execute this command:

       

      defaults -currentHost delete com.apple.syncservices SyncingDisabled

       

    Mac OS X Snow Leopard and Mac OS X Leopard
    1. Open the iSync application and navigate to iSync Preferences.
    2. Enable the option to "Enable syncing on this computer."
  5. Using the backup you created previously, import one calendar by choosing Import from the File menu. Verify that you can sync this calendar.
  6. Continue to import and sync one calendar at a time until all of them sync successfully or you discover one that does not sync.
  7. If your calendars still do not sync, consider contacting AppleCare for support. Removing the Sync Services folder is strongly discouraged.
  8. Once your calendars sync correctly, create a new backup using the procedure outlined above. This preserves any of the changes you made that fixed your sync issue.

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