After upgrading to Microsoft Azure AD Sync, Start-OnlineCoexistenceSync no longer exists.

From C:\Program Files\Microsoft Azure AD Sync\Bin>

DirectorySyncClientCmd.exe Delta

or

DirectorySyncClientCmd.exe Initial

Monitor the sync with this app:

C:\Program Files\Microsoft Azure AD Sync\UIShell\missclient.exe

Error:

The following error occurred during validation in agent ‘Windows LiveId Agent’: ‘Unable to perform the save operation. ‘Name’ is not within a valid server write scope.

Change the msExchRemoteRecipientType value from 4 to 3.