If you previously downloaded Sierra, check your tab in the App Store. You might find it there and can re-download it. If you deleted the file and the button is greyed out, hold down the Option (Alt) key on your keyboard while clicking the "Download" or "Cloud" icon.
The macOS Sierra 10.12.6 Update is intended for systems specifically running version 10.12.5. macos sierra 10.12.6 download
You must download the installer on a different Mac that is running an older OS (like High Sierra or Mojave) and copy the "Install macOS Sierra.app" to your target Mac via a USB drive or network transfer. If you previously downloaded Sierra, check your tab
macOS Sierra 10.12.6, released on July 19, 2017, is the final version of the operating system designed for older Mac hardware that cannot support newer updates. Although security updates ceased in 2019, the installer remains available for specific, older hardware configurations. Download the installer from Apple Support . The macOS Sierra 10
Download 10.12.6 only if a critical 32-bit app forces you to. For everything else, avoid it.
✅ You need to run ✅ You have a 2009–2011 Mac that can’t run High Sierra or newer ✅ You want a dedicated offline machine for retro computing