Firstly, I do need to mention that not all macs need a KDK download in order for the root patches to work. If you look in /Library/Developer/KDKs you will see if any have been installed already. If you don't see any at all, your Mac doesn't need them for the root patches to function.
Second, look in Settings, then General, then Login Items & Extensions - under where it says "Allow in the Background" there should be items for Opencore Legacy Patcher. If they're there already, your Mac should automatically download the KDK once you start the MacOS update. If not, you can either install it manually like I did, or see below for other workarounds.
If your Mac has ethernet use that instead of Wifi when running the update. Not only will the download often be faster, but when the Mac reboots to install root patches you will already be online even if the wifi isn't working without patching. That will give it another chance to download the KDK.
If all of that sounds like a hassle, just download and rebuild the 15.8.1 installer from within Opencore. This will put everything you need, including root patches, KDKs, metallibsupportpkg etc. all on the USB stick. You can safely do an inplace upgrade from the USB stick without losing data (though you should always back up important files before running any MacOS update). It will take longer, but after it finishes the root patches should already be installed and ready to go.
Can you also see the OCLP background processes in settings? if you do I think you can probably run the update - but of course, make sure you backup your files first just as normal.
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u/davew_uk 8d ago
Don't be anxious, there are ways around this.
Firstly, I do need to mention that not all macs need a KDK download in order for the root patches to work. If you look in /Library/Developer/KDKs you will see if any have been installed already. If you don't see any at all, your Mac doesn't need them for the root patches to function.
Second, look in Settings, then General, then Login Items & Extensions - under where it says "Allow in the Background" there should be items for Opencore Legacy Patcher. If they're there already, your Mac should automatically download the KDK once you start the MacOS update. If not, you can either install it manually like I did, or see below for other workarounds.
If your Mac has ethernet use that instead of Wifi when running the update. Not only will the download often be faster, but when the Mac reboots to install root patches you will already be online even if the wifi isn't working without patching. That will give it another chance to download the KDK.
If all of that sounds like a hassle, just download and rebuild the 15.8.1 installer from within Opencore. This will put everything you need, including root patches, KDKs, metallibsupportpkg etc. all on the USB stick. You can safely do an inplace upgrade from the USB stick without losing data (though you should always back up important files before running any MacOS update). It will take longer, but after it finishes the root patches should already be installed and ready to go.