If you are still using these old versions of the directory synchronization tool – DirSync and Azure AD Sync, it is time to move on and deploy Azure AD Connect to take advantage of the many improvements.
On April 13, 2017 DirSync and Azure AD Sync will not be supported anymore.
Go check what Azure AD Connect has to offer here https://docs.microsoft.com/en-us/azure/active-directory/connect/active-directory-aadconnect-version-history and download the latest version here http://go.microsoft.com/fwlink/?LinkId=615771