HELP - macOS shows prohibitory symbol during installation

TheNemesis47

New member
AMD OS X Member
Nov 22, 2025
1
0
1
CPU:
RX6650XT
Hi everyone,
I’m trying to install macOS on my AMD Ryzen system using OpenCore, but I constantly end up at the prohibitory symbol screen right after the Apple logo appears. Here’s the exact screen I’m getting.

My Hardware
• CPU: AMD Ryzen 5 7600 6 core(Zen architecture)
• Motherboard: B550 chipset
• GPU: RX6650XT
• Storage: NVMe SSD + USB for installer
• Boot mode: UEFI only
• Installer type: macOS Internet Recovery (MacOS Tahoe Recovery) using OpenCore

Kexts I’m using

These are correctly placed in EFI/OC/Kexts and enabled in config.plist:
• Lilu.kext
• VirtualSMC.kext
• WhateverGreen.kext
• AMDRyzenCPUPowerManagement.kext
• AMFIPass.kext
• RestrictEvents.kext
• AppleALC.kext
• SMCAMDProcessor.kext
• SMCRadeonSensors.kext
• SMCSuperIO.kext
• LucyRTL8125Ethernet.kext
• NVMeFix.kext
• UTBMap.kext

Drivers in EFI/OC/Drivers • OpenRuntime.efi • HfsPlus.efi

What I already checked
• Config rebuilt from scratch following Dortania (AMD Zen guide) and cheff kiss
• Kernel patches for AMD are present
• Reset NVRAM
• RestrictEvents + AMFIPass are enabled
• SMBIOS generated via GenSMBIOS (MacPro7,1)
• Booter Quirks follow AMD Zen requirements
• Kernel Quirks follow AMD Zen requirements
• All kexts updated to latest versions
• I am using macOS Internet Recovery, so the installer loads BaseSystem.dmg directly from Apple servers, not a full USB installer
- i even changed from 1000 to 5000 in info.plist of lan kext

I don’t know what to do now, on reddit someone asked me to add in boot-args> npci-3000 -no_compat_check but nothing happend
 

Attachments

Hi everyone,
I’m trying to install macOS on my AMD Ryzen system using OpenCore, but I constantly end up at the prohibitory symbol screen right after the Apple logo appears. Here’s the exact screen I’m getting.

My Hardware
• CPU: AMD Ryzen 5 7600 6 core(Zen architecture)
• Motherboard: B550 chipset
• GPU: RX6650XT
• Storage: NVMe SSD + USB for installer
• Boot mode: UEFI only
• Installer type: macOS Internet Recovery (MacOS Tahoe Recovery) using OpenCore

Kexts I’m using

These are correctly placed in EFI/OC/Kexts and enabled in config.plist:
• Lilu.kext
• VirtualSMC.kext
• WhateverGreen.kext
• AMDRyzenCPUPowerManagement.kext
• AMFIPass.kext
• RestrictEvents.kext
• AppleALC.kext
• SMCAMDProcessor.kext
• SMCRadeonSensors.kext
• SMCSuperIO.kext
• LucyRTL8125Ethernet.kext
• NVMeFix.kext
• UTBMap.kext

Drivers in EFI/OC/Drivers • OpenRuntime.efi • HfsPlus.efi

What I already checked
• Config rebuilt from scratch following Dortania (AMD Zen guide) and cheff kiss
• Kernel patches for AMD are present
• Reset NVRAM
• RestrictEvents + AMFIPass are enabled
• SMBIOS generated via GenSMBIOS (MacPro7,1)
• Booter Quirks follow AMD Zen requirements
• Kernel Quirks follow AMD Zen requirements
• All kexts updated to latest versions
• I am using macOS Internet Recovery, so the installer loads BaseSystem.dmg directly from Apple servers, not a full USB installer
- i even changed from 1000 to 5000 in info.plist of lan kext

I don’t know what to do now, on reddit someone asked me to add in boot-args> npci-3000 -no_compat_check but nothing happend
Hello @TheNemesis47 , the prohibited sign usually means the USB port you are using is not recognized after OpenCore starts to load. You are using UTBDefault.kext which basically does nothing as far as I am concerned. Beyond that I notice your EFI folder was likely borrowed from a laptop user. That is not the way you are going to get this done. There are other examples of B550 boards in the success story you can search for and modify likely with more success.
 
You need to clarify your hardware components, as the CPU and motherboard chipset you listed in post #1 aren't compatible.
  • CPU: AMD Ryzen 5 7600 6 core (Zen architecture)
  • Motherboard: B550 chipset
Which motherboard (make and model) are you using?
Which AMD Ryzen CPU are you using?
 
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