Is this because I'm using the free MS365?
I have a ~5y old bought version of Outlook, but am trying to use the free internet MS365 version for a mixed Group of Mac/Google/MS people needing to access and use a Group Calendar.
Two weeks ago, I managed to set one up for a few people, but had to delete it for other reasons; last week I successfully created a new Group, with Calendar, but am unable to add any members - be they icloud/gmail or even Outlook.com users, with the message "The following person couldn't be added. Try Again. Anybody know why, and how to fix this?
PS. https://support.microsoft.com/ says there's Chat support for Outlook.com users, but there's no "?" icon top right, only a lightbulb. Is Chat only available for paid versions?
