Request_BadRequest / 405

The endpoint does not support that HTTP method

Answer: The resource route exists, but it does not accept the GET, POST, PATCH, PUT, or DELETE operation used by the request.

Resolution playbook

Fix it, then prove it

Use the error record as the starting point; use tenant evidence to confirm the actual cause.

Do not retry a method error unchanged.
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.

Check the endpoint documentation for the supported method.
Confirm action and function routes include the required path segment and parentheses.
Verify whether the operation is supported only in beta or only on a different resource type.

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

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.

Inspect the active Graph PowerShell context

Get-MgContext | Select-Object ClientId,TenantId,Account,AuthType,Scopes

Read-only. Confirms tenant, auth type, and delegated scopes. For app-only tokens, also inspect the token roles claim.

Do not retry a method error unchanged.