When establishing a connection to the server on a Windows Mobile device, you may receive the message "Synchronization failed. Attention required." If you click on Attention required you will receive an error code to troubleshoot the issue.

The following error codes are described below:

ActiveSync error 0x86000108
ActiveSync error 0x80004005
ActiveSync error 0x85010004
ActiveSync error 0x86000C09
ActiveSync error 0x80883002

 ActiveSync error 0x86000108

Generally when you receive the error 0x86000108 for ActiveSync, it indicates that there is a corrupted item in the mailbox, contacts or calendar.

The best way to resolve this issue is to set the mailbox to download ALL ITEMS to the device. You can do this by navigating to the ActiveSync settings on the device: ActiveSync > Menu > Options > Mailbox / Calendar > Settings > Download ALL > OK.

If the issue persists, it is likely that the corrupted item is located in contacts. 

To find a corrupted contact:

  1. In Outlook, go to Contacts and choose to view the contacts by Company View.
  2. Once mailbox contacts are in this view, arrange the list by name (A on top). This brings all the empty lines and entries that start with blank spaces or special characters to the top.
  3. If you see any blank lines, delete them. If you see any fields with special characters or spaces, fix or delete that contact.
  4. Perform a re-synchronization of the mailbox. This should fix the problem.

If you still have problems, try this alternate solution:

  1. In Outlook, go to Mail.
  2. Create a temporary folder as a subfolder of the Inbox.
  3. Move all emails that are in the Inbox to the new temporary folder.
  4. Sync the device. It should sync successfully now.
  5. Move the emails back to the Inbox folder.
  6.  Sync the device again. It should sync successfully again and it should continue working.

If you are also having trouble syncing the calendar, try the following:

  1. In Outlook, go to Calendar.
  2. In the view menu, click Current View.
  3. Click By Category.
  4. Export all items to a PST file.
  5. Delete all calendar items.
  6. Sync the device. It should sync successfully now.
  7. Restore the calendar by importing the PST file.
  8. Sync the device again. It should sync successfully again and it should continue working. 

ActiveSync error 0x80004005

This error is caused by a corrupted item in the ActiveSync program on the device.

You will need to reset all the folders that you synchronized. To do this, navigate to ActiveSync > Menu > Options on the device. Uncheck Calendar, Contacts, Email and Tasks in the ActiveSync options (this makes the phone delete all synchronized content). Then re-select all the same options, so fresh copies of all the data will be downloaded.

ActiveSync error 0x85010004

This error occurs on ActiveSync devices when they attempt to authenticate without SSL enabled. Make sure that the device has SSL enabled and verify the settings. Then try to sync again. You should not receive the error anymore.

ActiveSync error 0x86000C09 or 0x80883002

This information applies to Exchange 2010 mailboxes.

These errors occur when there are too many mobile devices configured for the user's mailbox. To resolve the issue:

  1. Log in to the user's account using Outlook Web Access (OWA).
  2. Navigate to Options > Phone.
  3. Review the devices that are configured, and remove any unneeded devices.
  4. Re-activate the device that you are getting the error on.