I've downloaded "Install macOS High Sierra.app" from the Apple App Store. On launching I get:
"This copy of the Install macOS High Sierra.app application is damaged, and can‘t be used to install macOS."
This error can be fixed by following the steps (from https://discussions.apple.com/thread/7675283?start=0&tstart=0):
- Go to your applications folder.
- Find the installer.
- Right click on the installer and click "Show Package Contents".
- Click on the folder named "Contents".
- Click on the folder named "SharedSupport".
- Delete the file named "InstallInfo.plist".
- Enter your administer password to confirm.
- Now open the installer.
After deleting InstallInfo.plist, the installer runs. When it gets ready to restart, I get the error message:
"An error occurred while preparing the installation. Try running this application again." (see screenshot)
Searching for this error online suggests it can be linked to a mismatch between the system time and the time server, but my computer has the correct time and is set to update the time automatically.
I am currently running:
- OS X El Capitan version 10.11.6. (Note that I was also not able to upgrade to Sierra 10.12, with similar errors)
- MacBook Pro (Retina, 13-inch, Early 2015)
- Processor 3.1 GHz Intel Core i7
- Memory 8 GB 1867 MHz DDR3