A Microsoft file hosting and synchronization service.
No, all personal, pay for Microsoft 365 Family and have done for about 6 years. C:\Users\username\OneDrive is the problematic account, which just decided to break last week.
Do you have a Microsoft 365 Business account? If so, I'm wondering if it might somehow cause an issue with syncing your personal OneDrive to your computer.
Is your personal OneDrive folder, located at C>Users>username>OneDrive, syncing without issues?
My personal OneDrive works just fine, but I can't sync my folders to my computer because I'm syncing my folders to my Work account.
My personal OneDrive shows this at Manage Backup: