A Microsoft file hosting and synchronization service.
What worked for me after trying all the potential solutions in this thread was...
- Close OneDrive completely.
- Login to O365 and navigate to OneDrive.
- Click the "Get the OneDrive apps" at the bottom left.
- On the newly opened webpage, click "Start OneDrive".
- The OneDrive client reopened and made it past login.
Good luck with your troubleshooting.