I updated my 2012 mac pro today to High Sierra. I could not boot into windows 7 on boot camp thereafter. I got the dreaded black screen with "Bootcamp: no bootable device – insert boot disk and press any key" error.
I tried the third party utility gdisk suggested by David Anderson in 2018 but it did not work for me.
The hard drive that I boot from has 4 partitions:
- EFI System Partition
- MacHD Partition
- Recovery HD
When I entered three GPT partition numbers (2 3 4) as per david anderson's suggestion to use gdisk I got the following errors:
"Type from one to three GPT partition numbers, separated by spaces, to be added to the hybrid MBR, in sequence: 2 3 4"
GPT partition #2 does not exist or is too big: skipping
GPT partition #3 does not exist or is too big: skipping
GPT partition #4 does not exist or is too big: skipping
At first, I wondered if I should have only specified the bootcamp partition (#4) but then I realized that even that partition had the same error.
Can anyone offer some advice at this point? I really want my bootcamp to work. Thanks