title: Errors accessing Shared/Room Calendars through Microsoft Graph API
body: <p>I'm making an application that requires access to the shared/room-resource calendars in an Office 365 instance, using non-admin accounts. I've registered an app (in the Microsoft Application Registration Portal) using the V2 endpoint and Auth Code Grant. This successfully allows me to log in, and gives me a functional token with the <code>Calendars.ReadWrite.Shared</code> scope. With this token, I can retrieve my own calendars, and calendars that have been explicitly shared with me (and therefore added to <em>my</em> list of calendars). All of this is doable with just the normal <code>Calendars.ReadWrite</code> scope. </p>
  
  <p>However, I get errors when requesting access to any other shared calendars, like the room calendars. Here's an example. If I make a GET call to <code>https://graph.microsoft.com/beta/users/my-own-email@business.com/calendars</code> it successfully returns a list of my calendars. If I make a GET call to <code>https://graph.microsoft.com/beta/users/meetingroom1.4@business.com/calendars</code> I get a 404 (Not Found) Error. The same error occurs for any other user, not just meeting rooms. Note that I can see these calendars when I'm logged into Office 365 online with the same account.</p>
  
  <p>A different error occurs if I ask for events not calendars. If I make a GET call to <code>https://graph.microsoft.com/beta/users/meetingroom1.4@business.com/events</code>, I get a 500 (Internal Server) Error.</p>
  
  <p>I've checked all the other threads I can find on the issue, and this one from November <a href="https://stackoverflow.com/questions/40381513/how-to-access-shared-calendars-from-office-rest-api">How to access shared calendars from Office REST API?</a> says there's some kind of blocking issue on Microsoft's end. It's using the Office REST API rather than Graph, but on the back-end the APIs call the same stuff. Is this issue still about? Alternatively, am I missing some further permissions? I tried adding quite a few different permissions on top of <code>Calendars.ReadWrite.Shared</code>, but none of them fixed it. Is there a correct combination? </p>
  
  <p>Thanks so much for any help, and let me know if any other info would be useful for diagnosis. </p>