If you are having issues opening desktop Office applications (Outlook, OneNote, Word, Skype, …) after changing your Office365 password, you may have to clear the Windows Credential Manager on your PC.Close all Microsoft Office applications.
From the Start menu, select Control Panel.
Click User Accounts.
Click Credential Manager.
In the Windows Credentials and Generic Credentials section, remove all stored credentials referencing the Office 365 or Microsoft Office:
Select the Credential.
Click Yes on the warning box.
Repeat these steps until you remove all of the credentials associated with your Office 365 account.
Close the Control Panel window.
Launch the Microsoft Office.