Users unable to access Outlook on the web (OWA)

Issue:

While accessing Outlook on the web, the users receive the error mentioned below:

Resolution:

For 1 affected user (if possible a test user) Please connect to exchange online and then execute the below command:

Remove-MailboxUserConfiguration -Mailbox [e-mail] -Identity Configuration\IPM.Configuration.OWA.UserOptions

Solution provided by Microsoft. Reference case number #16350.