I need an image for Catalina so I can RE install it on a iMac that has gone crazy after automated install of Catalina. The iMac I have to do this with is running High Sierra and App Store won't let me download Catalina. What can I do?
If it is a 2011 or earlier iMac, then you cannot download the Catalina installer since a 2011 or earlier Mac cannot run Catalina (very frustrating Apple restriction).
If your iMac with the difficulties is running macOS 10.13+, then boot into Internet Recovery Mode using Command + Option + R which will bypass the local recovery partition when using Command + R.
Thanks for confirming the situation. I am in internet recovery mode on the machine now. Interesting!
How to download a MacOS Install Image for Catalina, using High Sierra?
