Users migrated to Office 365 have duplicate calendars called 'calendar' when using Microsoft Graph

Question

We're using an CRM that has switched to using Graph to add events into our users Office 365 calendars. We're getting error messages that there are duplicate calendars called calendar for some users, the users are all users who were migrated from on premise Exchange to Office 365.

Looking in Office 365 via Powershell (get-mailboxfolderstatics -Identity [email protected] -FolderScope Calendar | ft or in Outlook itself, there is only the one calendar named calendar.

But if I look at the same user via Graph

"@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('XXXXXXX-762d-47ee-9f82-XXXXXXXXXXX')/calendars", 

I see 2 calendars with name Calendar, only the changeKey is different between the 2 (same ID)

Azure support closed the case but the problem remains, how do I get Graph to see only the ONE calendar named calendar?

Answer 1

In the short term, one way to do this would be to fetch the calendar by id, then use the query parameters to customize the response using the changeKey. The longer term solution would be to engage your exchange admin to help with setting the right calendar for the users in question, which will eliminate the two calendars returned by graph.