Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.I have an iMac 21.5, 2017, 1tb ssd drive. I've never had an issue installing an OSX until this install. Does anybody have an answer that doesn't require me to formatt my hd? I left an image.
Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.
You'll need to erase your drive and perform a clean install.
Are you HFS, if so, yes.Does High Sierra support booting from an MBR drive?
Try to back up first, do you have an external drive or a Time Capsule? If so you should back up to it with Time Machine.Crap. I have to completly whip my drive? Is there something special I have to do when I format the drive?