If you have linked your Office 365 account to Airhead and see a red error message when using the Files widget:
It may be that you have not yet visited your OneDrive in Office 365. If you haven't visited OneDrive for the first time, your account will not yet be fully set up.
Browse to OneDrive and sign in to ensure your OneDrive account is set up and that you can browse your files. You should then be able to use the Files widget linked to Office 365. If you still receive an error message after completing these steps, please contact your support help desk.