But it is only helpful to fix minor problem. Disk Utility's First Aid is able to detect and repair damaged disk. Anyone can help me?'ĭisk Utility is a Mac build-in tool to manage internal disks and external storage devices. I searched it on the internet but didn't find a useful answer to fix 'APFS object map is invalid' error. But I got an error message: 'APFS object map is invalid'. 'I couldn't mount one of my APFS volumes on macOS High Sierra this morning, so I ran Disk Utility to check and repair it.
