Your Mac may sometimes throw an annoying error that says “An error occurred while generating the kernel cache“. This error message usually pops up at the end of a macOS update. You’re then prompted to quit the installer and restart your computer. But when you do that, your machine goes back to your previous macOS version. Let’s explore what you can do if the update process won’t complete.
Fix: MacOS Couldn’t Generate Kernel Cache During the Update
⇒ Important Note: Make sure to back up your data, if possible.
- Boot into Safe Mode. Shut down your Mac, and wait 10 seconds. Then restart the device, and immediately press and hold the Shift key. Release it when the login window appears on the screen. Wait for one minute and then boot up your Mac normally, and check for updates again.
- Create a new admin user account. If your current admin account got corrupted, create a new user profile with admin rights and check if you can install the latest update.
- Reset SMC and NVRAM. Reset your system settings, and check if the error is gone. For step-by-step instructions, go to Apple’s support pages:
Check Your Disk for Errors
- Restart your Mac, and immediately press and hold down the Command and R keys.
- Release the buttons when the progress bar appears on the screen.
- Select Disk Utility in the Utilities window, and click Continue.
- Select your main drive (for most users, it should be Macintosh HD).
- Click the First Aid option and wait until the tool scans and repairs your disk.
- Exit Disk Utility and check for updates again.
Reinstall MacOS in Recovery Mode
Try installing a fresh copy of macOS on your computer while keeping your data.
- Restart your Mac while holding the Command and R keys to boot into macOS Recovery.
- Release the keys when the Apple logo appears on the screen.
- When the macOS Utilities window appears on the screen, select the Reinstall macOS option.
- Make sure your Mac is connected to the Internet and hit Continue.
- Enter your password if prompted to unlock the startup disk.
- Wait for your Mac to complete the installation process.
- Login to your admin account and check for updates again.
Download the Combo Update Package
You can use this workaround if you want to install macOS Catalina or previous OS versions. As a quick reminder, it seems that Apple no longer offers standalone combo updates for Big Sur and later. The company hasn’t confirmed that the combo update packages are gone for good. However, Big Sur was released months ago, yet the combo update pack is nowhere to be found. Meanwhile, Apple is already working on the next macOS version, Monterey, expected to land in the fall of 2021.
To download previous combo updates, go to Apple’s download pages:
- Download macOS Catalina 10.15.7 Combo Update
- Download macOS Mojave 10.14.6 Combo Update
- Get macOS High Sierra 10.13.6 Combo Update
If you want to install the latest macOS release, you need to use the Software Update menu.
If the error persists, you can also use solutions available in the guides below:
- Fix: Installation Requires Downloading Important Content
- Mac: An Error Occurred Preparing the Software Update
- Stuck in a macOS update loop because there is not enough free space
If an error occurs while generating the kernel cache, and your Mac fails to install the latest macOS version, boot into Safe Mode, create a new admin profile, and reset the SMC and NVRAM. If the problem persists, check your disk for errors, and reinstall macOS in Recovery Mode. Did you manage to get rid of the kernel cache error and install the latest macOS updates? Let us know in the comments below.