Office 365 - SharePoint - Sync Issue: File/Folder Previously Synced
This article offers one possible solution to correcting a syncing issue experienced when a file or folder has previously been synced from SharePoint to OneDrive but a sync is not currently completing, and/or file(s) are not visible within File Explorer.
The below message may be displayed when attempting to sync a SharePoint file or folder that has been synced to OneDrive previously.
When this message is displayed, the likely issue is that a link to the SharePoint site exists within OneDrive that is not syncing appropriately and needs to be removed before a new link may be established.
To remove the issue link, navigate to SharePoint within an internet browser, then select the apps menu icon in the top left of the window. Select OneDrive from the menu options
Review the files being synced using OneDrive, looking for files that include a small chain link icon, indicating that they are linking SharePoint and OneDrive.
Select the linked file(s) that are found within OneDrive, then select "Remove" from the OneDrive menu options. Judgment may need to be applied to which file(s) to delete, if more than one SharePoint sites are being synced with OneDrive.
With the linked files having been removed that were causing the sync issue, syncing SharePoint files using OneDrive should now be possible. Navigate to SharePoint and attempt to sync the desired file(s)/folder(s).