Not able to select a disk to reinstall OS in safe mode I have iMac A1418 with High Sierra on it. I had to erase entire Macintosh HD disk hoping to reinstall OS on a ‘clean’ drive.

Unfortunately I’m not able to accomplish this as when I select “Reinstall macOS” in macOS utilities window and when it comes to selecting a disk on which I want to install OS, I can’t select a disk (Macintosh HD is displayed) and I can’t press “Install” button since it is greyed out.

It looks like window is waiting for me to click on desired disk - but I’m not able to do this because mouse is not functional and don’t see how I can select disk with keyboard.



I would appreciate any suggestions

UPD: eventually I resolved my issue by installing High Sierra on external SDD drive and booting iMac from it - this however doesn’t answer the question raised in this post.
When the drive isn't selectable, you almost always will want to choose Disk Utility and erase that volume.

Once it's totally erased, then run a repair operation to be sure the basic structure is good. Of course, you lose all data to do this erase, so be certain your backup isn't connected and is verified.

If the installer continues to fail, then you either have:


Wrong disk format entirely - post what diskutil list or disk utility shows for all the specifics of the volume format (APM/GPT) and the filesystem details (HFS / APFS / which flavor of the previous or some other like ext/fat)
A faulty installer 
Some faulty hardware