You ran OpenCore Legacy Patcher, restarted, and the Mac will not come back. Before trying fixes at random, answer one question: where exactly does it stop?
A Mac that shows a prohibited symbol, a Mac that boots only with the USB stick attached, and a Mac that hangs after root patching are three unrelated problems with three unrelated fixes. Applying the wrong one costs you an evening. This page maps the boot sequence stage by stage so you can identify your failure first, then jump to the fix that matches it.
Step 1: locate your failure on the boot sequence
A working OCLP boot passes through six stages. Find the last one you reached.
| Stage | What you should see | If it stops here |
|---|---|---|
1. Power on, holding Option | The Mac’s own boot picker, with an EFI Boot entry carrying the OpenCore icon | Black screen with no picker at all → unflashed GPU |
2. Select EFI Boot | The OpenCore Picker — OCLP’s own boot menu, visually distinct from Apple’s | Prohibited symbol 🚫 → unsupported SMBIOS |
| 3. Select the install target | The installer starts loading. Verbose text scrolls if you enabled verbose mode. | Black screen on a MacBookPro11,3 → safe mode needed |
| 4. Installer runs | Normal Apple installer — language, disk selection, progress bar | Hangs or errors → see our installer troubleshooting page |
| 5. First reboot mid-install | Installation resumes automatically | Back at the start of setup → setup loop |
| 6. macOS boots | Desktop, then run Post Install Root Patches | Hangs after patching → revert the snapshot |
Two failures do not fit the sequence, because they happen on an install that previously worked: the Mac only boots with the USB attached, and the Mac boots into Recovery endlessly. Both are covered below.
Stuck or black screen after root patching
This is the one that feels catastrophic — the Mac was working, you applied root patches, and now it will not boot. It is recoverable. macOS keeps a sealed snapshot of the system volume from before patching, and you can roll back to it.
This procedure requires macOS Monterey or newer. Big Sur does not support snapshot reversion — on Big Sur your route is a reinstall instead.
Reverting to the pre-patch snapshot
- Boot into Recovery. Press
Spacewhen your disk is selected in the OCLP boot picker. If the picker is hidden, holdESCat startup. - Open Terminal from the menu bar: Utilities › Terminal.
- Confirm your disk’s real name. The examples below use
Macintosh HD. If yours is named anything else, every path must be adjusted. Runls /Volumesto see the actual name. - Mount the volume as writable:
mount -uw "/Volumes/Macintosh HD"Then revert to the last sealed snapshot:
bless --mount "/Volumes/Macintosh HD" --bootefi --last-sealed-snapshotFinally, clear out the third-party kernel extensions that most often cause the failure, keeping the ones that are safe:
cd "/Volumes/Macintosh HD - Data/Library/Extensions" && ls | grep -v "HighPoint*\|SoftRAID*" | xargs rm -rfIf FileVault 2 is enabled, mount the Data volume before running that last command. In Disk Utility, find your macOS volume, select its Data volume, and choose Mount. Otherwise the path will not exist.
Restart. The system boots from the unpatched snapshot. You have lost the root patches — so graphics acceleration and other patched hardware are gone until you patch again — but the machine works, and you can investigate from a running desktop rather than a Recovery prompt.
Note the bless command above has no sudo. In Recovery you are already root. The same command run from a booted macOS does need sudo — that variant appears on our root patching errors page.
The Mac only boots with the USB drive attached
Everything works — until you pull the USB stick, at which point the Mac will not start. This is the single most common post-install complaint, and it is not a failure so much as an unfinished step.
By default, OCLP does not install OpenCore onto the internal drive during the install. OpenCore is living on your USB stick, and the Mac depends on it to boot. OCLP is supposed to prompt you to move it across once macOS is installed, but that prompt does not always appear.
The fix is to put OpenCore on the internal drive:
- The easy way: open OCLP and run Build and Install again, this time selecting your internal drive as the target.
- The manual way: transfer the OpenCore EFI folder to the internal drive’s EFI partition yourself, following the official OpenCore-to-HDD guide.
One step people miss afterwards: boot the machine holding Option and select the OpenCore entry from the internal drive at least once. The Mac’s firmware remembers the last entry you chose and auto-boots it from then on. Skip this and it may still look for the USB.
Prohibited symbol 🚫 or “This version of Mac OS X is not supported on this platform”
Both messages mean the same thing: macOS has detected an SMBIOS it does not support. In plain terms, macOS has looked at what the Mac claims to be and refused to run on it. That is exactly what OpenCore exists to prevent — so seeing this means macOS booted without OpenCore in front of it.
Almost always the cause is selecting the macOS installer directly in the Mac’s boot picker instead of selecting EFI Boot first. The order is not optional:
- Hold
Optionat startup → Mac’s boot picker - Choose
EFI Boot(the OpenCore icon) → OpenCore Picker loads - Now choose the installer or macOS from OpenCore’s menu
Once OpenCore has booted successfully a single time, the hardware auto-boots it from then on — until you reset NVRAM or remove the OpenCore drive.
The exception worth knowing: if the prohibited symbol appears after boot has visibly started — you saw the boot screen or verbose text first — the meaning changes. That points to your USB drive failing macOS’s integrity checks. Rebuilding on the same stick usually fails again; make the installer on a different drive, ideally a different model entirely.
Infinite Recovery OS boot loop
The Mac boots into Recovery, restarts, boots into Recovery again, forever.
OCLP relies on Apple Secure Boot so that OS updates work reliably. Doing so writes NVRAM variables that make sense to a Mac running OpenCore — and confuse a Mac that is not. If OpenCore is no longer in the boot path but those variables remain, the machine loops.
Fix: uninstall OpenCore and reset NVRAM — hold Option + Command + P + R immediately at startup and keep holding until the Mac chimes a second time (or the Apple logo appears and disappears twice).
There is a second, separate trigger for the same symptom: a machine with a modified root volume will loop in Recovery until volume integrity is restored. If you were root patching when this started, that is your cause — use the snapshot revert above rather than the NVRAM reset.
The Mac loops back to the start of setup after the first reboot
macOS installs in phases with a reboot in between. If that reboot lands you back at the beginning of setup instead of continuing, the machine is booting the wrong entry — it is starting the installer over rather than resuming it.
Power off, start up holding Option, choose EFI Boot, and then in the OpenCore Picker select the entry with a grey hard disk icon — it will read either macOS Installer or whatever you named the disk during setup. Not the USB installer entry.
Repeat after every reboot if it keeps happening. It is tedious rather than dangerous, and the install does complete.
Black screen on a MacBookPro11,3 running Monterey
This one is model-specific and macOS-version-specific: MacBookPro11,3 (the 15-inch Retina with the NVIDIA GT 750M), booting macOS Monterey. If that is not your machine and macOS version, this is not your problem.
Apple dropped NVIDIA Kepler support in Monterey. On this model the GMUX — the chip that switches between integrated and discrete graphics — then struggles to hand display output back to the iGPU, and you get a black screen before you ever reach a desktop where you could run the patches that would fix it.
Fix: boot into Safe Mode by holding Shift + Enter when selecting macOS Monterey in the OpenCore Picker. Once you are at a desktop, run OCLP’s Post Install Root Patches to restore acceleration for the NVIDIA dGPU. After that it boots normally.
No video at all — Mac Pro, Xserve or iMac with an unflashed GPU
If you have fitted a PC graphics card that was never flashed with Mac firmware, the card produces no output during boot. The machine is running; you simply cannot see the boot picker, which makes selecting EFI Boot impossible.
The way around it is to set OpenCore as the default boot device from a working macOS install, so no picker interaction is needed. From Terminal:
sudo nvram "recovery-boot-mode=unused" && sudo reboot recovery(Holding Command + R at startup works too.) Then, in the Recovery Environment, open Terminal from Utilities and:
- List the drives with
diskutil listand note the identifier of the disk holding your OCLP install. - Mount its EFI partition, replacing
Xwith the correct disk number:diskutil mount diskXs1 - Set OpenCore as the default boot device:
bless --mount /Volumes/EFI --setBoot --file /Volumes/EFI/System/Library/CoreServices/boot.efiA correct run produces no output at all. If anything is printed, you have mistyped something — check the command before rebooting. Reboot and OpenCore is now the default.
Getting into Recovery when Command-R shows a “no entry” sign
Several fixes above need Recovery, and on an OCLP machine the normal route often fails. Pressing Command + R hits Apple’s own unsupported-Mac checks and produces a no-entry screen.
Go through OpenCore instead. In the OpenCore Picker, press Spacebar to reveal the hidden entries — OCLP hides Recovery and other options by default — then select the Recovery entry matching your macOS version.
Before you assume the Mac is dead
- A slow boot is not a failed boot. On Macs lacking the AES CPU instruction, install stages involving heavy cryptography can take hours and look completely frozen. Tap
Caps Lock— if the light responds, the system is busy, not hung. - Never force a power-off during an install. It breaks the installation and commits you to starting over.
- A dead keyboard is not a dead Mac. If the machine boots but nothing responds, and it is one of the older models, you are likely hitting the USB 1.1 driver removal rather than a boot fault — see keyboard and trackpad not working.
- Check your model is actually supported. Two models cannot boot through OCLP at all. Our supported Macs list covers all 101 models and what to expect from each.
Procedures and commands on this page are compiled from the official Dortania troubleshooting and boot documentation, reproduced exactly as published. We are an independent community resource and are not affiliated with Dortania or Apple. For the authoritative reference see the official documentation; if something here is out of date, let us know.