A Microsoft file hosting and synchronization service.
Do you have 2TB of cloud storage on your Personal account? Do you also have a Work or School account syncing to your computer?
If your computer is considered a Work or School device, you will encounter these errors when connecting your Personal OneDrive to your computer if you are syncing the Windows Standard Folders (Desktop, Documents, Pictures, Music, Videos) to your work or school account. You cannot sync the Windows Standard Folders to both Work/School and Personal OneDrive accounts at the same time.