Microsoft 365 Group / Teams-connected sites surface access-denied on some
CSOM calls as a raw "(403) FORBIDDEN" WebException carrying
0x80070005 (E_ACCESSDENIED), not as a typed ServerException with
ServerErrorTypeName = System.UnauthorizedAccessException. IsAccessDenied
only matched the typed shape, so those denials became generic
InvalidOperationExceptions the elevation coordinator never caught — no
auto-elevation ran and the operation failed even for a SharePoint admin.
Walk the inner-exception chain and treat any of these as access-denied:
the typed ServerException, a WebException with HTTP 403, or a message
containing the E_ACCESSDENIED HRESULT. Per-site dedupe still caps elevation
to one retry, so a 403 elevation cannot fix (policy/endpoint block) won't loop.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
kawaandClaude Opus 4.8
1c36ea89d0