Remove users that are no longer existent or accessible in a target location.
Cleaning these users is important because they may have site permissions or documents marked as being authored by them. For more information on Orphaned Users, see here.
Note: External users can be temporarily flagged as orphaned users when they are created due to a short time lapse between Azure Active Directory and SharePoint that prevents synchronization.
Clean Orphaned Users
Target the item(s) you would like to clean orphaned uses from on from your Explorer tree.
Select Clean Orphaned Users from the Quick Actions menu in the right pane, under Security.
You will now see the Clean Orphaned Users page.
This table displays the targets you are cleaning orphaned users from. Please use this information to confirm that you are cleaning orphaned users from the right location(s).
Select the orphaned users you want to remove. You can select between All Orphaned Users or Specific Orphaned Users.
If you select Specific Orphaned Users, Start typing the name of the user to filter the results, or find them on the list below.
Once you have selected the user(s), click Clean Now.
You will now be prompted to confirm the action. Click Continue.
You will now see your results page (any warnings or errors, if applicable, will appear on a separate tab).