Even with a legitimate , errors occur. Here are the top fixes.
Third-party download aggregators often repackage the installer inside a fake DMG that prompts you to install "Mac Keeper" or other unwanted software. Always verify the checksum (MD5/SHA1) of your downloaded DMG against known-good values.
Disclaimer: This article is for educational purposes. Always respect Apple’s software licensing agreements. This guide was accurate as of publication; Apple may alter download links at any time.
The installer is the final maintenance release of the "OS X" era, primarily serving as a critical bridge for older hardware to reach modern versions like macOS High Sierra or Monterey. How to Download (Official Method)