This solution is related to the error message: "Couldn't Log In, Unhandled exception ocurred during login."
This issue is related to a Credential Manager issue on your Windows 10 installation.
To resolve this you should:
- Go to the Windows Start menu.
- Type in "Services" and select the "Services" Desktop app.
- Right-click "Credential Manager" and Start or Restart your Credential Manager service.
Please see below...