Hi @Tanya De Lange ,
What detailed version of Outlook are you using? (File > Office Account > About Outlook)
Is OWA disabled in your organization?
According to my search, I have found that it only affects those 365 organizations that have Resources configured.
An update to Semi-Annual Enterprise Channel seems to fix this issue：
For more information about changing the 365 Channel, refer to this article：
(Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)
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