While your Mac model may support macOS Sonoma, not all features may be available. Certain features require specific Mac models with Apple Silicon.

Finally, though it may seem obvious, make sure that you are using the proper standalone updater for your system -- either the standard Mac OS X 10.4.2 client or Mac OS X 10.4.2 Server.

Latest Mac OS X El Capitan updates, issues and fixes In this article we cover the features that have arrived with OS X in El Capitan so that you know what to expect.