When I get to the point where I select the disk to install the new OS, I can't select Macintosh SSD. It says "This volume is not formatted as APFS". And I'm stuck here. The disk seems normal, everything seems normal. See attached screenshot (in Norwegian).
iMac 21.5", macOS 10.14
Back up the Mac.
Boot into Recovery and open Disk Utility.
Select Macintosh SSD.
Select “Convert to APFS” from the Edit menu.
If successful, retry upgrade.
Back up the Mac.
Boot into Recovery and open Disk Utility.
Select Macintosh SSD.
Select “Convert to APFS” from the Edit menu.
If successful, retry upgrade.
And this will not erase the hard drive ?
It shouldn't. That doesn't mean you shouldn't have a current backup of the drive.
Upgrading from macOS Mojave 10.14.2 to macOS Catalina 10.15.4
