Unable to Boot into macOS Tahoe Installer

[Andrew1]

I'm looking to upgrade from Ventura to Tahoe, but I'm unable to boot into the installer USB (booting into Ventura installed on my NVMe SSD is fine): I posted a screenshot of where the kernel panic happens (debug enabled on OC, Kexts, and Drivers). I mapped all of the correct USB ports with USBMap. Safe mode doesn't work for the installer either. I triple checked my config.plist and BIOS settings against the Dortania guide: there doesn't seem to be anything out of the ordinary.

Has anyone else had a similar issue or know the cause of this?

 

Specs:

CPU: Intel Core i5-10400 (Comet Lake)

GPU: AMD Radeon RX 6600 8GB

Motherboard: MSI Z490-A PRO

SMBIOS: iMac20,1

 

On the IGPU: I'm getting stuck on "launching: ipc (mach)" (with WhateverGreen.kext disabled)

EFI.zip

Edited September 19, 2025 by Andrew1

[crazybirdy]

If it's USB issue, and can't find the USB root device to boot installer,

I suggest you to split a 20GB partition from SSD or HDD to make createinstallmedia installer.

This should solve the "can't find USB root device issue".

 

 

Edited September 19, 2025 by crazybirdy

[Vinicius P. Miranda]

Your WhateverGreen.kext is activated and it doesn't work well on the Tahoe. Set its Max Kernel to 24.99.99, and it will work up to the Sequoia.
It looks like this:

 

The problem is that the screen goes black after the display goes to sleep and doesn't come back on. I don't know how to fix this yet, but I'm looking into it.
If this DeviceProperties refers to the iGPU, you need to remove or comment it out (by adding a # at the beginning of the name, like #Pci...). If the iGPU is enabled in the BIOS, disable it.

Test this to see if it works.

Edited September 21, 2025 by Vinicius P. Miranda

[Andrew1]

18 hours ago, Vinicius P. Miranda said:

Your WhateverGreen.kext is activated and it doesn't work well on the Tahoe. Set its Max Kernel to 24.99.99, and it will work up to the Sequoia.
It looks like this:

 

The problem is that the screen goes black after the display goes to sleep and doesn't come back on. I don't know how to fix this yet, but I'm looking into it.
If this DeviceProperties refers to the iGPU, you need to remove or comment it out (by adding a # at the beginning of the name, like #Pci...). If the iGPU is enabled in the BIOS, disable it.

Test this to see if it works.

 

I tried both of these suggestions, and now I get stuck somewhere else

[Vinicius P. Miranda]

@Andrew1
Your setup is very similar to this guy's in this post. Try comparing his to yours and adjusting. He wrote a great post, and I picked up some of his stuff too.
Remember to update your signature with your hardware.
https://www.insanelymac.com/forum/topic/361500-macos-26-tahoe-with-opencore-105-z390-i9-9900-rx-6600-xt/

Edited September 22, 2025 by Vinicius P. Miranda

[ken]

This is what I do to install Tahoe 26.1 in my machine

Bios :

- reset bios or clear cmos (if needed remove the cmos battery and disconnect from all power electricity for few second with push the power button)

- DIsable CMS

- Setting only UEFI Boot

- Disable Onboard graphics

 

Make installer :

1. Create full installer USB Tahoe 26.1 image (in my case I download macOS image using my friends macbook and create the usb boot on there using command here )

2. In My PC windows download OpCore Simplify from here and run it, in my case it's will detect the best macOS, kext and setting for your PC

3. Map your USB using USBToolBox from here, I dont change any setting in there just export the kext

4. After All finish you will have EFI folder, I using OpenCore Auxiliary Tools open config.plist to remove USB default kext or something like that Kernel section.

5. Drag your USBmap kext your got from USBToolbox to OpenCore Auxiliary in kernel section and save.

6. After create macOS USB boot finish mount the EFI partition and copy EFI folder you create before to that partition

7. Momen of truth boot to your USB and install macOS and work in my case.

8. After all install done, mount EFI partition again in USB and macOS Harddrive, copy EFI folder your create before to EFI partition macOS Hardrive.

9. In my case my sound doesn't appear, I'm using MyKextInstaller follow the instruction there and reboot and the sound appear.

10. In my case the sleepwake sometimes not working, so I disable it following command from here.

11. Done and I hope that help

Spoiler

Screenshot

 

 

[Andrew1]

On 9/22/2025 at 7:14 AM, Vinicius P. Miranda said:

@Andrew1
Your setup is very similar to this guy's in this post. Try comparing his to yours and adjusting. He wrote a great post, and I picked up some of his stuff too.
Remember to update your signature with your hardware.
https://www.insanelymac.com/forum/topic/361500-macos-26-tahoe-with-opencore-105-z390-i9-9900-rx-6600-xt/

 

I followed the above steps and also did some more debugging and resolved the following issues:

1) The installer USB was corrupt: I remade it and got further.

2) The USB 3.0 port was causing "still waiting for root device" error (with prohibited sign), so I switched to a USB 2.0 port.

 

3) The biggest unresolved issue: Even with the MacPro7.1 SMBIOS, I am getting a black screen (no signal to be exact) on both monitors. The IGPU is disabled. I've tried changing my DeviceProperties -> Add options to what was suggested, but it didn't make a difference. The problem is that so far, I've only avoided black screens with WhateverGreen.kext, but WhateverGreen is causing stalls when booting (see attached picture when using WhateverGreen.kext).

 

Is there a way to fix the black screen/no signal on both monitors without using WhateverGreen?

Edited December 13, 2025 by Andrew1

[matxpa]

Hi

Did you try with Laobamac's WhateverGreen (WhateverGreen-1.7.1d7) instead of Acidanthera one ?

WhateverGreen-1.7.1d7 available on [Pre Release] macOS Tahoe 26.1 forum, page 9

Regards

Edited December 13, 2025 by matxpa

[Slice]

But the PR was rejected.

[Max.1974]

On 12/13/2025 at 5:46 AM, Andrew1 said:

 

I followed the above steps and also did some more debugging and resolved the following issues:

1) The installer USB was corrupt: I remade it and got further.

2) The USB 3.0 port was causing "still waiting for root device" error (with prohibited sign), so I switched to a USB 2.0 port.

 

3) The biggest unresolved issue: Even with the MacPro7.1 SMBIOS, I am getting a black screen (no signal to be exact) on both monitors. The IGPU is disabled. I've tried changing my DeviceProperties -> Add options to what was suggested, but it didn't make a difference. The problem is that so far, I've only avoided black screens with WhateverGreen.kext, but WhateverGreen is causing stalls when booting (see attached picture when using WhateverGreen.kext).

 

Is there a way to fix the black screen/no signal on both monitors without using WhateverGreen?

 

 

Does your card prefer using WhateverGreen, or does it work with the NootRX kext? 

 

https://chefkiss.dev/applehax/nootrx/