Need help regarding install of 10.13.6

[graveyar1987]

Hello

I have a Imac mid 2011 generation and High sierra is the last Mac OS update i can get, I am running 10.12.6 Sierra presently and a software i need to use requires 10.13.

I downloaded the file from the app store for 10.13.6 but whenever i try to install it gives an error saying "an error occurred while preparing the installation".. I have tried multiple times, even downloaded the installation files again from the app store, even tried the time and date, even tried installing through recovery. even tried apple support but havent been successful yet.

Any help would be highly appreciated

 

[Brian33]

How big is the downloaded installer (the 'Install macOS High Sierra.app' file)? The full installer should be about 5.23 GB, according to my saved copy. After dowloading the installer, Quit out of the Installer program and look at its size in /Applications.

Here's an idea that might work: you should be able to use the full installer to make a bootable installer on a USB flash drive (using Terminal commands -- google for instructions, as the commands may be specific to High Sierra). After that's created you boot your iMac off the flash drive and install HS.

 

[timidpimpin]

Create a bootable installer for macOS - Apple Support

You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system.

support.apple.com

 

[mdgm]

There are unsupported hacks to run newer versions of OS X than High Sierra.

The big problem is that the stock graphics card doesn't have metal support so performance is terrible though there are reports of a 3rd party patch that should work well on Catalina and with minimal support on Big Sur that is expected to be released soon.

There's a long thread on replacing the graphics card with a metal compatible one to run newer Mac OS.