How to Fix a Frozen Mac When Updating macOS

While macOS is a very robust operating system, sometimes there can be hiccups when performing system updates. I experienced this firsthand when updating my new and right-out-of-the-box Mac Mini to macOS Sierra from OS X Yosemite. In my case, the progress bar stopped and stayed that way for a few hours.

If you are experiencing a frozen Mac when updating the system, here are a few ways to save your data, attack the problem, and solve the issue.

Preliminary Precautions

As always, before performing a system update of any kind, make sure you have all of your sensitive data backed up.

If you’re here because your Mac is already frozen – which I’m willing to bet most of you are – still, don’t worry. Chances are your data will remain intact. Just make backing up your data a priority in the future.

Also, don’t update macOS if your hard drive is running out of space. I’d recommend keeping at least 30GB free. Now, onto solving the problem.

1. Let It Sit

As painful as it sounds, you may just want to let the Mac sit for a couple of hours and see if it is indeed frozen. Sometimes, the update could be stuck in a lull but not completely frozen. Some update processes will take much longer than others, resulting in a seemingly stuck progress bar.

We can verify that the system is still updating by pressing “Command + L” to bring up the estimated install time. If this doesn’t appear, still let the update sit for a while.

Some users have reported their update taking upwards of ten hours. Grab a coffee, do some other work, run some errands, do whatever you need to do to burn some time and let your Mac do its thing. Big system updates (sometimes) take a whole lot of time!

2. Refresh The Update

If you are positive that the install is indeed frozen, you will want to take the following steps, and the following steps consecutively after this step, until the issue is resolved.

Let’s try to give the install a little kick by refreshing it.

1. Hold down the power button and wait for about 30 seconds.
2. When the Mac is completely off, press and hold the power button again. Now, the update should resume.
3. Press “Command + L” again to see if macOS is still installing.

If there is no avail, continue onto the next solution below.

3. Reset Your NVRAM

NVRAM, as Apple describes it, is “a small amount of your computer’s memory that stores certain settings in a location that macOS can access quickly.” It also happens to hold kernel panic information, which is what we’re tapping into and especially trying to reset here.

1. Press and hold the power button on your Mac to completely shut it off. Hard discs and fans need to stop spinning, and the screen needs to go dark.
2. Power on your Mac.
3. Immediately after you hear the startup sound, press and hold the “Command + Option + P + R” keys.
4. Keep holding them down until you hear the start up sound again.
5. Release the keys, and the NVRAM will have reset. The update should resume.

4. Recovery Mode

If the update still won’t complete, we can download macOS from the Internet and give the install another shot. Instead of trying to fix the existing hiccup, we would be effectively starting over with the update.

1. Press and hold the power button to turn off the Mac.
2. Press and hold the power button to turn it back on.
3. Press “Command + R” immediately to enter recovery mode.
4. Once in recovery mode, connect to the Internet. You’ll need to click the WiFi symbol located at the top right of the menu. Preferably, do this from a home network.
5. You can now download the most current version of macOS and install! Select “Reinstall OS X” or “Reinstall macOS” and the on-screen GUI menu will guide you through this.

Conclusion

Hopefully these steps were able to get you back on track. If not, you are advised to contact Apple Support for a further look.

As stated, these hiccups rarely do happen, but when they do it is nice to know that macOS includes features capable of working them out.