You can close the wizard at this point as you do not need to complete it for re-authentication to take effect. You should run a test sync after re-authenticating the sync to ensure it is working. Now, we will verify the server settings to fix the Outlook synchronization error. The sync will fail if the groups you selected to load users from no longer exist in Azure AD.

Common Causes of Sync Issues in Outlook

Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow. There can be several reasons for the Outlook synchronization error. Before we know the solutions, we will understand a few common causes of the Outlook sync problem. Find out what to do if you are having issues with syncing users or groups from Microsoft 365. It is possible for a corrupted Outlook profile to impede synchronization.

Fixing problems with directory synchronization for Microsoft 365

Another which is shown below, is a user opens a new message, or replies to one, and lets it sit for a while. When they go back to the message and press repair corrupted OST in Outlook send they get an error that the message has been deleted. Ive repaired the OST and changed cache mode to only cache 1 year.

• The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile.
• If you don't wish an inactive user to be made active by the M365 sync, you can add the user's email address to the sync forbid list.
• The sync will fail if the total number of all users (active or inactive) on your account exceeds the user limit placed upon it if present.
• After the files get repaired, restart the Outlook program to ensure that the Outlook syncing issues are resolved or not.
• Outlook sync issues can be because of corrupted Outlook OST or PST files.
• Firstly, we will discuss a few manual methods to resolve this Outlook error and share the stepwise procedure of each method to successfully fix synchronization issues.

Use the Microsoft Support and Recovery Assistant

If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook. If users are facing syncing issues in Outlook due to corrupt Outlook data files, they must choose a professional tool, like Shoviv OST to PST Converter Tool. This software allows users to process numerous OST files at once without any size limitations. Moreover, it maintains the folder hierarchy and metaproperties of the data when processing Outlook data files.

How to Fix Outlook Sync Issues in Windows?

The sync will fail if it can't find any users that comply with your filtering preferences or the system's requirements for user records. The system requires that users have a first name, last name and a valid email address that conforms with your domain lock if enabled. The sync does not delete users but rather sets them to inactive. The idea is to provide a repair corrupted OST in Outlook recycle bin of users who you can delete when you no longer need them.





You can view your inactive users on the Users page and delete them as you see fit. Similarly you should review work offline mode stuck the Users Deactivated sheet on the sync summary spreadsheet attachment as you can also delete these users to bring your total down. I have multiple users experiencing sync errors with Outlook and office365.

What should I do if my sync fails because it can't find any users?

After these instructions, ensure the sync settings are correct and check everything is working well. To make sure there are no issues, click Test Account Settings to test the connection. Test other programs or websites to be sure Outlook is the only problem.



This blog talks about the causes behind Outlook synchronization errors and a few solutions to fix Outlook sync issues. We have shared five manual methods in this blog to resolve the Outlook syncing errors. Apart from this, we also discuss the Shoviv OST to PST Converter Tool, a professional way to repair, recover, and convert Outlook data files. This solution will be beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files. Users can also try its free demo version in their system and process the first 50 items from each folder freely. Always make sure your profile and settings are set up correctly, your software is up to date, and your connection is steady.