MP 1,1-5,1 Prohibited Sign after installing Blackhole Sound Extension

[wyattaj25]

Hey all -

This post is unrelated to my journey of installing a Titan Ridge in my 5,1 last year (which was sucsessful, if you have questions, feel free to ask.) Usually im pretty good at diagnosing and fixing mac pro issues but i personally havent seen this before.

I gave my little brother my old single processer 5,1 which I am no longer using. He's just using it for Minecraft and starting to work in VS code. He wanted to record his minecraft gameplay with desktop audio, so he installed Blackhole which is used to pickup audio from the OS and send it to OBS. after he installed it he needed to restart the machine, it gives a prohibited sign after going through the Opencore boot picker.

i've tried going into recovery and removing the extension via terminal, to no avail. Reset PRAM/NVRAM, booting into safe mode didnt work, rebuilding the kernel cache did nothing.

When booting into verbose mode all it did was go through for a bit and hang at "waiting for remote debugger connection."

 

[reader50]

Perhaps some more info? Installed PCIe cards, version of macOS, version of OC? Do you have macOS installed on another partition or drive, so you can confirm the 5,1 boots normally from another install?

Try an SMC reset, though that's more typically an answer after a hardware change.

 

[wyattaj25]

Perhaps some more info? Installed PCIe cards, version of macOS, version of OC? Do you have macOS installed on another partition or drive, so you can confirm the 5,1 boots normally from another install?

Try an SMC reset, though that's more typically an answer after a hardware change.

OCLP Version is REL-101-2024-08-05, macOS is 12.7.6, only PCI-E card is GPU, macOS is installed on the same drive as the OCLP installation, on a different partition of course.

How do you perform an SMC reset? I havent had to do one yet and am only familiar with PRAM/NVRAM resets.

Thanks for the suggestion, and let me know if this info helps!

 

[reader50]

To reset SMC on a 5,1 - pull the power cord (or switch off power, if plugged into a switched outlet). Wait at least 15 seconds. Plug back in (or turn power back on). Wait at least 10 seconds before booting.

What model is the GPU?

Do you have another macOS install available to test bootability? Assuming 'yes' and it boots OK - then reinstall Monterey on top of your regular volume. Your data will be fine.