A Microsoft file hosting and synchronization service.
Make sure to close One drive then do the following steps: C:\Users%username%\AppData\Local\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy\AC\TokenBroker\Accounts [Delete all files] HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\ [Delete identity folder]C:\Users%username%\AppData\Local\Microsoft\OneDrive\settings - [Delete all files]HKEY_CURRENT_USER\SOFTWARE\Microsoft\OneDrive\Accounts - [Delete Business1 folder] AFTER COMPLETING THESE STEPS RESTART YOUR COMPUTER
This should solve the issue and allow you to sign in now.