Want to upgrade OS from 10.13.6 to 10.15.7
I tried and received an error message that it was "not possible"...
iMac 21.5″, macOS 10.13
In betwen 1.13 & 10.15 was 10.16... macOS Mojave 10.14.6 - Technical Specifications
General Requirements
OS X 10.8 or later
2GB of memory
12.5GB of available storage (OS X El Capitan 10.11.5 or later)*
Some features require an Apple ID; terms apply.
Some features require a compatible Internet service provider; fees may apply.
Mac Hardware Requirements
For details about your Mac model, click the Apple icon at the top left of your screen and choose About This Mac. These Mac models are compatible with macOS Mojave:
MacBook (Early 2015 or newer)
MacBook Air (Mid 2012 or newer)
MacBook Pro (Mid 2012 or newer)
Mac mini (Late 2012 or newer)
iMac (Late 2012 or newer)
iMac Pro (2017)
Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)
https://itunes.apple.com/us/app/macos-mojave/id1398502828?mt=12
Thanks to MartinR Terminal command…
softwareupdate --fetch-full-installer --full-installer-version 10.14.6
It will place a copy of the installer in your Applications folder and you can use that to create a bootable installer.
Possible workarounds for not being able to upgrade...
Mostly you just need a more modern Browser than Safari on Catalina, Mojave, or High Sierra like Firefox or Brave.
https://www.mozilla.org/en-US/firefox/83.0/system-requirements/
Details about recent download Brave, for 10.13.6/10.14.6 are here:
<https://github.com/brave/brave-browser/releases/tag/v1.57.64>
Firefox 83.0 System Requirements (mozilla.org)
Opera…Thanks
