How to solve 3 big macOS Sierra problems


Here are three problems we've run into so far.
Photo: Ste Smith/Cult of Mac

By now, most of you are probably upgraded to macOS Sierra, which is proving be a massive home run for Apple. However, while the new Mac OS packs some great new features, it’s also got a handful of problems — ranging from strange error messages to Wi-Fi issues.

Check out our video below for three macOS Sierra problems we’ve run into so far — and how we were able to solve them.

Three macOS Sierra problems we’ve run into

Mac apps that are “damaged and can’t be opened”

Don’t panic if you get this message. There are things you can do to sort it out. For starters, try following these steps:

1) Empty your Mac’s cache, by using the Finder window and selecting Go to Folder in the Go menu. Next, type in ~/Library/Caches and hit enter to go to that folder and empty it.
2) Try holding down command + option when you launch the app.
3) Another explanation could be an issue with your Mac’s security settings. Go to the Security and Privacy system preferences, and check the Allow applications downloaded from: Anywhere setting.
4) Try resetting your computer’s PRAM. To do this, shut down your Mac and turn it back on. As soon as you hear the startup sound, hold down command, option, P and R. Hold these down until you hear the computer restart and the startup sound playing for a second time.

Mac runs slowly after macOS Sierra upgrade

We’ve all been there: You upgrade to the latest OS, which looked amazing on all of Apple’s demos, but find that your once-speedy Mac now crawls along in slow motion. While this could have you reaching for the credit card to order an upgraded Mac, however, there are other things you can try first:

1) Reduce your RAM usage, or possibly upgrade it to make your machine run faster. To easily check which apps are using the most memory, launch Activity Monitor and check the Memory tab is selected. You can then banish the widgets or memory-hogging apps causing your machine to run slowly.
2) Try resetting your computer’s PRAM, as described above.
3) Repairing disk permissions with Disk Utility can also have a big impact.

Slow Wi-Fi after macOS Sierra upgrade

Slow Wi-Fi is every bit as annoying as a slow Mac. Here are a few solutions to help you banish this nightmare scenario back to the 2002-era dystopian past it came from:

1) Power off your router and check if it requests any updates. You can also try turning off Bluetooth.
2) Try de-selecting proxies, which you do by going to System Preferences > Network > Advanced > Proxies Tab, and then unchecking any box ticked under Select Protocol. Hit OK, and then Apply.
3) If these suggestions don’t work, you can try deleting your existing Wi-Fi preferences. This means removing system configuration files, so make sure you back up your Mac first. Start by quitting any apps that are using Wi-Fi, then turn it off using the Wi-Fi menu. Next, use the Go folder and select Go to folder.

Now enter: /Library/Preferences/SystemConfiguration/

Next, select the following files:

Remove these by either putting them in a folder on your desktop or moving them to trash. Now reboot your Mac and, when you’re back up and running, turn back on the Wi-Fi. Hopefully this should immediately work as usual.

Any other macOS Sierra problems?

These are three of the problems we’ve so far faced with macOS Sierra, but inevitably there will be other teething issues some users face. We’ll be back with another installment of this series. In the meantime, are there are problems you’ve personally run into on the new operating system? Leave your comments below.

  • Adel Gabot

    Keyboard problems! My keyboard has lost the functionality of the left/right arrow keys, the letter “i” and several others.

  • Tim Brown

    The show more or show less when you have things sorted by kind in finder is borked .. also mail is struggling and sometimes wont load emails , the fix is to close mail and re open but that is very annoying safari sometimes stalls and wont load web pages but again its a close and open again and sorted thing.. other than that the Sierra is fine :)

  • Rausth Borges

    Trackpad not ignored when Magic Mouse is paired even with the option at SystemPreferences/Accessibility/MouseAndTrackpad marked( checked).

  • Gaurav Pandey

    Every year almost same issues :(

  • thinkfurther

    I have a problem that Airport Utility can no longer find attached storage on my AirPort Extreme.

  • Gabriel Tondin

    Yes! The huge and boring trouble with external ultrawide-screen monitors connected by HDMI that doesn’t work.

    • TrueNorth_Steve

      yup big problem – lost that option too.

    • Kel Dommage

      Same here, but it seems fixed in today’s update (25 Oct 16)

  • quicklookd, it kills my iMac almost every time I open finder, to the point I have to keep activity monitor and terminal open just to force it to quit, several times over before it stops….. Only happens on my iMac, not my MacBook Pro 13″.

  • Joe Streno

    You realize that “Allow applications downloaded from: Anywhere” does not exist in macOS 10.12. Apple in it’s paranoia hid it from mere mortals in stock Sierra. You have to use Terminal and type:

    sudo spctl –master-disable

    Hit return and authenticate with an admin password.

    Quit System Prefs if open, then open the Security & Privacy system prefs & the choice should be back again.

  • kk

    I have a huge heating problem after the upgrade and no one else seems to experience the same issue : (

  • viktike

    Missing PPTP VPN client. Now I use Shimo VPN to solve it.

  • Jed Fish Gould

    Glad it’s a massive home run fir Aplle. Not for me. Music production and all.
    By the way, why does Apple still — after all of the lame changes they have made — still call it finder? That is just dumb and the worst 80s idea ever. Thoughts?

  • ŠâŁmäñ HäíÐeŕ ĸħän

    How to fix Charge time ? I have retina macbook pro, i7 15 inch (2015) prior on El Capitan it’s battery backup time was 8-9 hours, now since upgrading to Mac Sierra, it’s hardly 3 hours :(

  • Kel Dommage

    Shutdown or Restart – there’s a long pause (presumably something in the cache or a kernel extension) that freezes the Mac for upwards of 10 minutes, then reboots. And this is on a current (pre-announcement) MacBook Pro 13″ with 512GB SSD (but not so on an old late-2009 iMac with a 1TB spinning HD)

  • Igor Degtiarenko

    You can free up some RAM using CleanMyMac app. Worked fine for me. And it resets caches too.

  • John Vassiliou

    I have noticed another problem of MacOS Sierra: When you try to change the default browser from a browsers preferences, the dialog window that comes up is hidden behind all your application windows… You have to look for it to change the default browser.

  • Mac OS Sierra is fine .But System Integration Protection (SIP)is enterily terminal!!

  • Victor

    Since the update my Time Machine backups take ages and nothing helps to speed them up.
    Before 1GB of backup took maximum 6 min now its almost 2h

  • Ludger Weß

    Still can’t unlock my iMac with Apple Watch, App Store indicates >10 available updates but doesn’t list them in the Updates tab.

  • Joe Kelley 

    After the Sierra upgrade, connecting to any network share causes a prompt for credentials. Even if you click the checkbox telling macOS to save the credentials in your keychain, the next time you try to mount the same network share the prompt appears again. The credentials are filled in, but you have to click the “Connect” button. As an IT manager, this is causing all kinds of trouble. I created many Automator workflows and Applescripts to run at login and automatically connect network shares, but now nothing happens until the user clicks “Connect”. I could understand if this were a security feature, but macOS remembers the credentials and fills them in! This is just an annoyance.

  • Zebbyz

    Copy speed from a GoPro card to the USB3 hub has gone through the floor… like 5 mins… WTF… as has copy speed gone through the floor from the USB3 hub to a USB Thumb drive.

  • Martin

    My one won’t even turn on after the update.. Lovely!