OpenCore booted, the installer started, and then something went wrong — a greyed-out button, an error you cannot get past, or a progress bar that has not moved in two hours. These are installer-phase problems, distinct from the boot problems covered on our Mac won’t boot page, and each has a specific cause.
Find your symptom below. One of them is not a fault at all, and knowing which could save your installation.
Stuck on “Less than a minute remaining…” — do not touch it
Read this before doing anything else, because the instinctive response is the one that destroys the install.
The “Less than a minute remaining” stage is where macOS performs a large amount of cryptographic work. On Macs that lack the AES CPU instruction — and on older mobile hardware generally — that work is done in software rather than in dedicated silicon, and it is slow. The estimate is wrong by orders of magnitude.
This step can take a few hours or more, depending on drive speed. The machine looks frozen. It is not.
To confirm the system is alive rather than truly hung, press the Caps Lock key. If the light turns on, the system is busy and responding. That is your signal to leave it alone.
Do not power off or reboot to “unstick” it. Interrupting this stage breaks the installation and you will have to start the whole process again. Plug the Mac into mains power, walk away, and check back in a few hours.
“An error occurred preparing the software update”
This appears in the second phase of the installer — the one with a black background and the Apple logo, after the first reboot.
The honest answer, and the one the official documentation gives: the cause of this issue is unknown. Nobody has pinned it down.
The equally honest fix is that it is transient. Keep rebooting into macOS Installer — the second-phase entry — repeatedly until it goes through. It usually does, sometimes after several attempts. There is no configuration change to make and nothing you did wrong.
If instead of this error the machine drops you back at the beginning of setup after that reboot, that is a different problem with a real fix — see the setup loop section.
Continue button greyed out on the disk selection screen
You reach the “select the disk where you want to install macOS” screen, your disk is visible, and the buttons will not respond.
The fix is unexpected but reliable: switch the installer language to English. The disk selection screen misbehaves under some other language settings, and English clears it.
If the language selector never appeared, reset NVRAM (hold Option + Command + P + R at startup) and boot the installer again — the selector should show this time.
You can switch macOS back to your preferred language once installation has finished. The constraint applies only to the installer.
“Your Mac needs a firmware update in order to install to this Volume”
The full message reads: “Your Mac needs a firmware update in order to install to this Volume. Please select a Mac OS Extended (Journaled) volume instead.”
Do not take its advice. Installing to HFS+ is not what you want.
The error occurs because macOS has decided the Mac’s firmware lacks full APFS support. The fix is to have OpenCore report firmware that does: when building OpenCore, open Patcher Settings and set SMBIOS Patching to Moderate or higher. Rebuild, reinstall OpenCore, and boot the installer again.
The internal disk is missing when building OpenCore
OCLP reports that it cannot find applicable disks, and your internal drive is nowhere in the list. This happens with a brand-new disk that has never been used, or one never formatted in any macOS format — OCLP needs somewhere recognisable to place the EFI.
Two ways out:
- Create a small FAT32 partition. In Disk Utility, add a partition of around 100MB — the name does not matter. OpenCore will detect it and you can build your EFI there.
- Format the whole disk properly during install. In Disk Utility choose View › Show All Devices, then select the topmost entry in the sidebar — the physical device, not the volume beneath it — and format that.
The second option is the one to be careful with if you own a Touch Bar Mac — see the warning below.
T1 Macs: wiping the whole disk destroys Touch Bar functionality
This one is permanent damage from a routine action, so it is worth knowing before you reach the disk-format step rather than after.
On T1 Macs — the 2016 and 2017 Touch Bar models — installing macOS Sonoma or newer while wiping the entire disk will remove T1 functionality. That means the Touch Bar and Touch ID stop working.
Wipe only the volume containing the operating system, not the whole disk. In Disk Utility that is the indented volume entry, not the top-level physical device. The distinction is one click and it is not reversible from within the installer.
If you have already done this, recovery steps are documented in the official hardware troubleshooting guide — the boot documentation defers to it rather than covering the repair inline.
“You don’t have permission to save” when creating the USB installer
This one happens earlier — while you are still building the installer, before any boot attempt. OCLP reports that the bless of the installer disk failed, with a permission error.
OCLP needs Full Disk Access. Grant it:
- Ventura and Sonoma: System Settings › Privacy and Security › Full Disk Access
- Big Sur and Monterey: System Preferences › Security and Privacy › Full Disk Access
Enable OpenCore-Patcher in the list. If it is not listed, click + and add it from your Applications folder. Restart OpenCore Legacy Patcher and try creating the USB again.
If you would rather not leave the permission in place, you can remove OCLP from Full Disk Access once the USB drive is made.
“Volume Hash Mismatch” popup on Monterey
A dialog appears saying the boot volume’s hash does not match what the OS expected. It looks alarming and generally is not — it is cosmetic and can be ignored.
Worth knowing: this bug affects natively supported Macs too. It is not caused by running an unsupported machine, so it is not evidence that your OCLP install is broken.
Two caveats. If the system starts crashing spontaneously shortly after the popup appears, treat it as real — reinstall macOS fresh, without importing data on the first pass. And if it recurs, disabling FeatureUnlock in OCLP’s Settings › Misc Settings can help, since that tool is demanding on systems with weaker memory stability.
Still stuck?
- If the failure happens before the installer loads — prohibited symbol, no boot picker, black screen — see Mac won’t boot after OpenCore Legacy Patcher.
- If OCLP itself errors while patching — error code 71, version mismatch, helper tool missing — see root patching errors.
- If the installer runs but you cannot type — that is the USB 1.1 removal, covered in keyboard and trackpad not working.
- Before troubleshooting further, confirm your machine is supported and check what to expect from it in our supported Macs list.
Error text, menu paths and fixes on this page are compiled from the official Dortania troubleshooting and boot documentation. 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.