Recently, I have users who can't open shared calendars in Mac. It says they don't have permissions however, they can open the calendars on a Windows computer or online but for some reason not on the Outlook for Mac 2016. I've even tested with me on my test MacBook and can't and I'm running the Office Insider version. I can on the OWA and on the Windows laptop. Is there a fix for that? Is there a solution? We are using Office 365.