When you use the Microsoft Azure Active Directory Sync tool, you notice that synchronization of objects from your local Active Directory to Microsoft cloud services such as Office 365, Azure, or Microsoft Intune has stopped. Additionally, the following event is logged in Event Viewer:
Event ID: 0
Source: Directory Synchronization
This version of the Directory Sync Tool is not supported. You may be running an older version of the Directory Sync Tool. Make sure you are running the latest version. You can obtain the latest version by downloading it from the Directory Synchronization page in your Admin Portal. If the error persists, contact Technical Support.
This problem occurs if you're using a version of the Directory Sync tool that's no longer supported. We no longer accept connections to Azure Active Directory (Azure AD) if you’re using a version of the Directory Sync tool that is too old or that was recalled.