Users who are NOT using 'the new outlook' are not affected. The issue seems to be tied directly to 'The new Outlook' option being enabled in the online version of O365 ( ). This is a huge deal, because we schedule many public spaces and manage staff schedules through shared calendars. The calendars still appeared, they just weren't modifiable. At the University of Pennsylvania, our Office365 users suddenly lost 'edit' access to the shared calendars they had previously set up in their O365 calendars.
