Action: Have users run the "Easy fix" tool to fix file names When you use OneDrive for Business to sync SharePoint Online, ...

Action: Have users run the "Easy fix" tool to fix file names When you use OneDrive for Business to sync SharePoint Online, OneDrive for Business, or SharePoint libraries to your computer, you may have to rename a wide range and large number of files if their names contain invalid and unsupported characters. You should have your users run the Easy fix tool against their personal file shares and update folders and files to a supported format. The tool requires that the OneDrive for Business Sync Client be installed; however, it doesn't have to be configured.