I'm trying to create a Mojave installer on my MacBook Pro running Catalina using the createinstallmedia technique. Everything seems to work fine, installer is created with no errors, but when I try and set the USB stick as the startup disk, I get the error "the bless tool was unable to set the current boot disk." How do I fix?
MacBook Pro 15”, macOS 10.14
What is the format and partition map (should be Mac Os Extended and GUID)? Does resetting PRAM help? Tried another flash drive or to re-download the installer?
It’s probably not bootable. Restart holding down the Option key and see if it appears in the Startup Manager.
If it doesn’t, try creating it again.
lenonator wrote:
Yes, it appears, allows me to select it, but won't continue booting/installing
Sounds like there is something wrong with it, or that OS can’t boot your Mac.
Did your Mac ship with Catalina or Mojave? If Catalina, Mojave will not be able to boot that Mac.
Yep, Extended and GUID. Reset PRAM, did not help. I guess I'll try another flash drive.
And yes, I have set my security prefs to allow booting from external media.
Yes, it appears, allows me to select it, but won't continue booting/installing
I've created an installer using two different machines, same problem both times. Mojave came with my MacBook, so that's not the issue.
I don’t have any other suggestions
Can't bless startup disk
