Close Microsoft Outlook and do the following to clear the credentials in Windows 10 for Microsoft Outlook:

1. Hit the Windows Key on your keyboard.
2. Type credential manager and open up the Credential Manager application that shows up from your search.
3. Select Windows Credentials.
4. Remove all credentials relating to Microsoft. To delete an item, click on the downward pointing arrow to the right of each item and then click Remove.
5. Items to remove:
   1. MicrosoftOffice16_Data: ....  (delete all these items)
   2. outlook.office365.com
   3. SSO_POP_Device

Reopen Microsoft Outlook. You may have to reenter credentials.