firmware update iMac 27" late 2012
Updating Mojave to Catalina. First I was told I need to change my hard disk from HFS+ to APSF -form. I divided the hard disk with section for APSF and downloaded Catalina. Then I got message "You need to update the firmware. Choose HFS+ instead.
What now I can do?
iMac 27″, macOS 10.14