Updating your Mac offers more than access to Apple’s new features. macOS updates address security concerns, improve system stability, and provide compatibility with the latest apps or tools.
Yet, many users still encounter situations when their Mac won’t update. These issues often prevent people from using their computer or retrieving stored data.
The experts at Secure Data Recovery, an Apple Authorised Service Provider (AASP) with Apple Certified Mac Technicians (ACMT), explain why Macs won’t update.
Why macOS Won’t Update
In most cases, the issue is not with Apple’s servers but with the Mac itself. These problems do not just delay updates. They also create long-term risks.
A few common culprits include:
- Insufficient Storage Space
- Unstable Internet Connection
- Corrupted System Files
- Outdated Hardware
- Conflicting Software
Fix 1: Check Your Internet Connection
If your Wi-Fi drops out or slows during the update process, the update may stall or fail entirely.
To troubleshoot:
- Switch networks. If you are on public Wi-Fi, try moving to a private, secure network.
- Restart your router. A simple reboot often resolves connection glitches.
- Use Ethernet. Connecting directly to your router via cable provides more stability than Wi-Fi.
- Check Apple’s System Status. Occasionally, Apple’s update servers experience downtime. Visit the official Apple System Status page to confirm.
Note: In some cases, if internet speed is not the issue, firewall or VPN settings may be blocking the update servers. Temporarily disabling these tools can help identify their impact.
Fix 2: Free Up Disk Space
macOS updates require far more space than the size of the installer alone. This is because the system needs temporary room to unpack, copy, and configure files during installation.
To check your available space:
- Click the Apple menu in the top-left corner.
- Select About This Mac, then Storage.
- Review the breakdown of storage categories to see what’s consuming space.
If storage is limited, try the following:
- Remove large, unused files.
- Clear system junk. Temporary files and caches can be safely deleted with Apple’s built-in cleanup tools.
- Move files to external storage or iCloud. Photos, music, and documents can be shifted to free up space.
- Empty the Trash.
Editor’s Note: As a rule of thumb, aim for at least 20–25GB of free space before installing a major macOS update.
Fix 3: Restart and Try Safe Mode
Sometimes the simplest solution is the most effective. If a basic restart does not help, Safe Mode offers a more powerful option.
Safe Mode works by running basic diagnostics, clearing the system cache of potentially corrupted files, and loading only essential software.
To start in Safe Mode:
- Shut down your Mac.
- Press the power button, then immediately hold the Shift key.
- Release the key when you see the login screen.
- Log in, then try rerunning the update.
On Apple silicon Macs, the process differs slightly. Shut down your Mac, hold the power button until “Loading startup options” appears, then select your startup disk, press and hold Shift, and choose Continue in Safe Mode.
Once the update is complete, you can restart normally and continue using your Mac without restrictions.
Fix 4: Reset NVRAM and SMC
Two components often overlooked during troubleshooting are the NVRAM (Non-Volatile Random-Access Memory) and the SMC (System Management Controller). Both store low-level settings that influence how your Mac starts, runs hardware, and communicates.
Resetting NVRAM
NVRAM holds information such as speaker volume, screen resolution, and startup disk preferences. Corruption in this memory can prevent updates from installing correctly.
To reset NVRAM on Intel-based Macs:
- Shut down your Mac.
- Power it back on while holding Option + Command + P + R.
- Keep holding for about 20 seconds, then release.
On Apple silicon Macs, NVRAM resets automatically during startup if needed, so no manual action is required.
Resetting SMC
The SMC controls power management, battery charging, cooling fans, and other essential functions. If these systems misbehave, they can indirectly cause update failures.
To reset the SMC on Intel Macs:
- Shut down your Mac.
- For laptops with non-removable batteries, press Shift + Control + Option + Power for 10 seconds, then release and restart.
- For desktops (iMac, Mac mini, Mac Pro), unplug the power cord for 15 seconds, reconnect, and restart.
On Apple silicon Macs, the SMC reset is built into the restart process. Simply shutting down and restarting refreshes its functions.
Note: Resetting NVRAM and SMC can resolve stubborn update problems by clearing hidden settings that interfere with the installation process.
Fix 5: Update via macOS Recovery
When regular update methods fail, macOS Recovery provides a more reliable fallback.
How to Enter macOS Recovery
- Intel Macs: Restart your Mac and immediately hold Command + R until you see the Apple logo or spinning globe.
- Apple silicon Macs: Shut down your Mac. Hold the power button until you see “Loading startup options,” then select Options, then Continue.
Reinstalling macOS
Once in Mac Recovery, choose Reinstall macOS from the Utilities window. This process downloads the latest compatible version of macOS for your device and installs it over your existing system. Importantly, this does not erase your files, apps, or settings.
Why recovery helps:
- It replaces corrupted system files that might be blocking the update.
- It bypasses third-party software conflicts.
- It ensures you’re installing the most stable version of macOS for your hardware.
Fix 6: Check for Compatibility Issues
Before investing time in troubleshooting, confirm that your Mac model supports the version you are trying to install. Apple publishes an updated list of supported devices on its official site.
Check Hardware Compatibility
- Click the Apple menu, then About This Mac, to identify your model and year.
- Compare this with Apple’s compatibility list for the latest macOS.
- If your Mac is unsupported, you will need to remain on your current version or consider a hardware upgrade.
Address Software Conflicts
Even if your hardware is supported, certain third-party applications can interfere with updates.
To rule this out:
- Temporarily disable or uninstall non-essential apps before retrying the update.
- Ensure all critical apps and drivers are updated to their latest versions.
Advanced Troubleshooting
These methods are best for users who are comfortable with macOS’s command-line tools and system utilities.
- Use Terminal for Updates. Open Terminal and type softwareupdate -l to list available updates. Running softwareupdate -i [update name] can sometimes install updates that fail via System Preferences.
- Create a Bootable Installer. Download the macOS installer from the App Store and use a USB drive to create a bootable installer. This bypasses system conflicts and installs macOS directly.
- Check Disk Health. Using Disk Utility > First Aid helps detect and repair disk errors that could block updates.
Editor’s Note: Always back up your Mac before attempting advanced troubleshooting.
When to Seek Professional Help
If your Mac still refuses to update after trying these solutions, the issue may indicate deeper hardware or storage problems. In particular, a failing hard drive or SSD can prevent updates from installing correctly. Continuing to attempt updates in this state risks worsening data corruption.
Secure Data Recovery offers specialised expertise tailored precisely to Mac data recovery. Our team delivers a hassle-free process with reliable results, featuring a No Data, No Recovery Fee guarantee.
Call us at 0800 102 6925 or request help today to receive a free quote and regain important data.
