Fixing 'Stop Sign' Error on MBP A1278 (Sonoma)

By Ufuk Durgun
0

Resolving Prohibited Sign during Sonoma Boot

The 'stop sign' (prohibited symbol) on your 2013 MacBook Pro means the Mac found the OS but couldn't read the kernel due to a security policy mismatch.

The Fix:

  1. SIP Settings: Ensure System Integrity Protection (SIP) is disabled in OCLP settings before creating the installer. Sonoma requires it to be off to load legacy kexts.
  2. Library/Extensions: If you updated from 10.13, old kexts might be conflicting. A Clean Install is highly recommended.
  3. USB Port: On the A1278, try using the USB port closest to the screen, as it often has better stability during the EFI boot phase.

Original Question: "Problem installing Mac Sonoma onto a Mac book pro A1278"

Hey, I have a Mac bookpro from 2013 (A1278), currently in 10.13.

I tried to install Sonoma 14 through OCLP (last version of it, download today) but failed in the end.
I followed this tuto https://www.youtube.com/watch?v=D8djeFJ1czU&t=627s
Everything went fine until the reboot, I select EFI (oclp logo) and Install Sonoma. I have an apple logo then (seem fine) and then a "stop sign" and like "contact apple support".

I tried several time, always stuck here.
Can you help me here ?
Thanks 😄

submitted by /u/frozenjb
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