Hi everyone,
I’m running into an issue while trying to retrieve the mailbox usage CSV using the Microsoft Graph Reports API.
I’m calling:
GET https://graph.microsoft.com/v1.0/reports/getMailboxUsageDetail(period='D30')
The request succeeds initially but returns a 302 redirect to a temporary download URL on:
https://reportsncu.office.com/data/v1.0/download?token=...
When I follow this redirect (either automatically with code or manually), the download URL consistently returns:
404 Unknown
What I’ve already verified:
- The Azure AD App Registration has Reports.Read.All (Application) permission
- Admin consent has been granted
- The app successfully retrieves an access token
- Other Microsoft Graph API calls work without issues
- The API endpoint itself does return a redirect token (so authentication seems OK)
How to resolve this issue?