I have a macbook pro late 2012, single stock SSD, Sierra installed with latest updates. I am trying to install High Sierra.

When I go to select the disk to install on (the current, normal boot volume), the installer refuses, with the error: "This disk cannot be used to start your computer"

Disk Utility First Aid can find nothing wrong. The computer boots normally just fine with Sierra.

Volume name : Macintosh HD
Volume type : Logical Volume
BSD device node : disk1
Mount point : /
File system : Mac OS Extended (Journaled, Encrypted)
Connection : PCI
Device tree path : IODeviceTree:/PCI0@0/PEG2@1,2/SSD0@0/PRT0@0/PMP@0
Writable : Yes
Is case-sensitive : No
File system UUID : 308F1BD9-CF92-335C-B437-D47C941E7D76
CoreStorage UUID : 0E3E3C70-5FE7-484E-826B-828CDA8F3471
Parent CoreStorage LVG UUID : 13CB696B-1760-4072-A883-0ED19EFBEBF1
Volume capacity : 374,756,999,168
Available space (Purgeable + Free) : 168,884,392,284
Purgeable space : 9,433,788,764
Free space : 159,450,603,520
Used space : 205,872,606,884
File count : 1,735,041
Owners enabled : Yes
Is encrypted : Yes
System Integrity Protection supported : Yes
Can be verified : Yes
Can be repaired : No
Bootable : Yes
Journaled : Yes
Disk number : 1
Media name : Macintosh HD
Media type : Generic
Ejectable : No
Solid state : Yes
S.M.A.R.T. status : Not Supported
Parent disks : disk0s1
  • 3
    I'm having the exact same issue. I am however, dual booting Windows alongside MacOS. Are you too?
    – Fredefl
    Sep 25, 2017 at 21:42
  • 2
    I'm having the same issue and I've got dual boot too, iMac 2017 5K with fusion drive Sep 26, 2017 at 4:21
  • 1
    @Fredefl I had a dual-boot linux partition, but I deleted it a while ago and added the space back to the mac disk. So it appears the issue revolves around having multiple boot partitions (now or in the past).
    – marathon
    Sep 27, 2017 at 15:40
  • 2
    Unfortunately, I have had the same issue. Spent time with Apple support but could not solve it. I too have a dual boot machine.
    – Tin
    Oct 3, 2017 at 1:57

4 Answers 4


You must turn off filevault before install HS...

  • 3
    While this may provide an answer to the question, it's good to provide supporting links/documentation explaining why your answer is correct.
    – Allan
    Sep 27, 2017 at 17:52

My wild guess would be: remove rEFInd from the EFI or replace your current EFI partition (disk0s1) with a new one. Afterwards first backup and then remove any additional partition after disk0s3 (but not a recovery partition) and any second logical volume and finally expand the CoreStorage LVG to the full size of either 512 or 768 GB (depends on your SSD).


I had the problem described here on my MacBookPro12,1 (Retina, 13-inch, Early 2015) running El Capitan, during attempts to upgrade to both High Sierra and Monterey.

This answer led me to gpt -r show disk0, which reported output similar to the output reported here, including Suspicious MBR at sector 0, and MBR rather than PMBR.

The accepted answer suggests using gdisk to replace the hybrid MBR with a legal protective MBR. Rather than installing gdisk on MacOS, I followed the advice in this answer and used the Ubuntu gdisk.

All of this seems consistent with the comments following the question, which suggest that this problem is more likely with dual booting.

After the Ubuntu gdisk invocation, both Ubuntu and MacOS still booted successfully, and the Monterey installer accepted the MacOS partition as a target. Monterey is running now on that Mac, and Ubuntu still works also.


I solved this by doing a full time machine backup, Booting recovery mode, bringing up diskutility there and reformating the disk.

Then did a restore from time machine.

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