I am able to install macOS High Sierra with a flash drive to my Mac (late 2015) but if I create a usb flash drive of macOS Monterey with it and try to use it, it doesn’t work. While installing, the computer just resets at the 14 to 15 minute left mark. I have tried to just install it while on high sierra but it does the same thing. I have tried macOS Big Sur and it does the same thing. Can someone help me on this?
AFAIK iMac late 2015 model should run up to Monterey and High Sierra should have updated the firmware to APFS support. Does resetting PRAM and SMC help? Do you by chance have a 3rd party internal drive which AFAIR Monterey might not support?
AFAIK iMac late 2015 model should run up to Monterey and High Sierra should have updated the firmware to APFS support. Does resetting PRAM and SMC help? Do you by chance have a 3rd party internal drive which AFAIR Monterey might not support?
What is the file system being used on the destination drive for the full Monterey installation? If the destination is to be the internal SSD with High Sierra currently installed, then you need to be using the APFS file system for the Monterey installer to work, otherwise it will fail at some point in the process. I thought the Big Sur installer would automatically convert the file system if needed, but perhaps later versions of the Big Sur installer have changed.
Is the internal SSD the original Apple OEM SSD or a third party replacement?
Edit: I restarted the computer after the “less than a minute remaining” came on and it booted up as if it installed macOS Mojave
How do I reset the PRAM and SMC? I have a 2tb HDD from factory. I have tried to install Monterey with APFS and other file systems and they both reset at the same point.
I just tried installing MacOS Mojave with a flash drive I made with my Mac laptop and it gets stuck on “less than a minute remaining”.
Why can’t I install any other macOS other than High Sierra?
