When you try to add your account to OneDrive for Mac, you may receive the error: "You're already syncing this account."
- From Spotlight search type “keychain” and select " Keychain Access”. If it's not visible in Spotlight, go to the Utilities folder and open Keychain Access from there.
- Search for “OneDrive.”
- Delete “OneDrive Cached Credential.”
- Go to /Users/<username>/Library/Group Containers/
- Find and delete UBF8T346G9.OneDriveSyncClientSuite.plist and UBF8T346G9.OfficeOneDriveSyncIntegration.plist
- Restart OneDrive.