Older macOS installers often fail because their security certificates have expired. If you get a "damaged" error during installation: The Date Trick:
Apple still provides the OS X Mavericks 10.9.5 Combo Update as a direct download. Note that this is an update and typically requires an existing installation of Mavericks to run. Creating a Bootable USB Installer
You’ve got the DMG on a USB. Now you reboot holding the Option (Alt) key. Here’s what can go wrong:
If you have the Mavericks installer (a .dmg file), you can create a bootable USB drive:
If you get an "installer is damaged" error, it's usually an expired certificate. Use Terminal in Recovery Mode to set your system date back to 2014 ( date 0101010114 ).
Before attempting to install, ensure the target hardware meets these specifications:
Older macOS installers often fail because their security certificates have expired. If you get a "damaged" error during installation: The Date Trick:
Apple still provides the OS X Mavericks 10.9.5 Combo Update as a direct download. Note that this is an update and typically requires an existing installation of Mavericks to run. Creating a Bootable USB Installer
You’ve got the DMG on a USB. Now you reboot holding the Option (Alt) key. Here’s what can go wrong:
If you have the Mavericks installer (a .dmg file), you can create a bootable USB drive:
If you get an "installer is damaged" error, it's usually an expired certificate. Use Terminal in Recovery Mode to set your system date back to 2014 ( date 0101010114 ).
Before attempting to install, ensure the target hardware meets these specifications: