gatz wrote:
I need to restore a 13.3.1 Timemachine backup. My machine is at 13.4. TM requires the same operating system. It tells me to reinstall 13.3.1 and use migration assistant. But as near as I can tell you can’t downgrade. Am I missing something?
Not quite sure what you are saying here..."I need to restore a 13.3.1 Timemachine backup" ???
You do not say exactly what is your current issue...
restore items backed up with Time Machine
Restore items backed up with Time Machine on Mac - Apple Support
If you are determined you can download the full installer 13.3.1 It requires erasing, reformatting, initializing the parent drive as new...to fall backwards.
Create a bootable installer for macOS - Apple Support
software updates available Installers via terminal:
softwareupdate --list-full-installers
ex.
sudo softwareupdate --fetch-full-installer --full-installer-version 13.3.1