Users are seeing duplicated shared Calendars when switching from Calendar module to Mail module and back to the Calendar module when opening a REST shared Calendar. FIXED. A fix for this issue has been released in build 16.0.15926.10000.

You can work around this issue by taking the following steps: Remove the affected calendar (s) from Outlook Desktop. Enable “Turn on shared calendar improvements” in the Calendar Properties. For information about how to turn on this setting, see Outlook calendar sharing updates. Restart Outlook Desktop.

Outlook for Microsoft 365. We've made major updates to the way Outlook for Windows connects to and updates shared calendars. These improvements are available to all Outlook 365 customers that are using the latest Monthly Enterprise Channel, Current Channel, or Semi-Annual Enterprise Channel.

If you have an Exchange, Microsoft 365, or Outlook.com account, you can send a sharing invitation to other users so they can view your calendar in their own Calendar list. Calendar sharing isn't limited to the default Calendar folder that is created in all Outlook profiles.

Share your calendar in Outlook.com. Get solutions if your calendar won't sync or you can't edit shared calendars in Outlook.

Shared mailboxes stop updating automatically. The shared mailbox status in the bottom bar in Outlook Desktop will show “Updating this folder”. In addition, you can confirm this is the issue by looking at the Sync Issues folder of the primary Exchange account in the Outlook profile.

Cause. This problem occurs because the time zone information is stored in a configuration message that is in the root of the mailbox. A user who does not have full access permission to a shared calendar, cannot access the time zone information. Therefore, the server time zone is used. Resolution.

This issue occurs because the store worker process (Microsoft.Exchange.Store.Worker.exe) caches the security contexts that are not updated for the token of the account when you access a shared folder. It means that the security contexts do not contain the necessary group membership information.

When you receive the sharing invitation in your inbox, accept the invitation from Outlook on the web, iOS, Android or from Windows 10 Calendar. Note that the calendar owner can share the calendar from any Outlook app, but it’s easiest to do currently in Outlook on the web, iOS, or Android.

Video: Create a shared calendar in Office 365. A team site calendar helps keep your team in sync by sharing everyone’s meetings, project milestones, and vacation time. Watch this short video to learn more. View a video that will show you how to create a shared calendar using Office 365.