Microsoft Graph service is temporarily unavailable

Likely causes

• Distinguish a transient 503 from persistent authorization or request-shape failures.
• The token is missing, expired, for the wrong audience, or contains the wrong delegated/application permission type.
• Consent, Microsoft Entra role, licensing, resource ownership, or endpoint-specific authorization is still insufficient.

Recommended fix

1. Honor Retry-After when present and use bounded exponential backoff.
2. Check Microsoft 365 service health for a matching incident.
3. Preserve request and correlation IDs for escalation.

Verify

1. Acquire a new access token after permissions or consent change.
2. Confirm delegated permissions appear in scp or application permissions appear in roles, and that aud targets Microsoft Graph.
3. Repeat the exact HTTP method and endpoint and confirm the response no longer returns the same request ID/status.

Escalate when

• The failure persists after the documented prerequisites and a new authentication/session attempt.
• Multiple users, apps, devices, or networks show the same error, suggesting tenant policy or service scope.
• You can provide the exact UTC time, tenant, application/resource, correlation or request ID, and sanitized logs.