How To Update Macos High Sierra 10136 To 1015 (2025)

| Step | Action | |------|--------------------------------------------------------------| | 1 | ✅ Verify Mac compatibility with Catalina (2012 or newer) | | 2 | ✅ Full Time Machine backup | | 3 | ✅ Check & update 32-bit apps – expect breakage in Catalina | | 4 | ✅ Free up 30+ GB storage | | 5 | ✅ Download “Install macOS Catalina” from App Store | | 6 | ✅ Run installer, keep Mac plugged in | | 7 | ✅ After reboot, run Software Update for latest 10.15.x | | 8 | ✅ Reinstall 64-bit apps & reconfigure permissions |

Restart your Mac, hold Cmd+R to enter Recovery Mode. Use Disk Utility to run First Aid on your startup disk. Then try the installer again. how to update macos high sierra 10136 to 1015