To 1015 — How To Update Macos High Sierra 10136

Transitioning from 10.13 to 10.15 changes system files, user permissions, and the underlying disk structure. A failed update can result in data loss. Therefore, you must perform a full to an external drive. For additional safety, consider cloning your startup disk using software like Carbon Copy Cloner. Crucially, do not skip this step; Catalina converts the system volume to a cryptographically signed, read-only “Signed System Volume,” and while this usually works seamlessly, reverting is difficult without a backup.

Select your main drive (usually "Macintosh HD") as the destination. Enter your when prompted. how to update macos high sierra 10136 to 1015

If your Mac is officially unsupported but you still want to update, community tools like the OpenCore Legacy Patcher can help, though these are for advanced users only. How to update macOS on your Mac | Apple Support Transitioning from 10

If you're trying to update to a very specific version (e.g., for compatibility reasons), you might need to use the macOS Recovery mode or download the installer directly from the Mac App Store. However, Apple usually encourages users to stay on the latest version of macOS for security and feature updates. For additional safety, consider cloning your startup disk