The new macOS Sierra update is now available to download and install for OS X 10.11 El Capitan users. As of now, most of you have upgraded to macOS Sierra, some users may have experienced issues with the new upgrade. If you also have experienced issues with macOS Sierra then proceed below to know the various macOS Sierra issue and the ways to fix them.
Also, we had wrote about the 3 most common macOS Sierra issue which a Mac user may have faced.
See it here: 3 Most Common macOS Sierra Problems and their Fixes
macOS Sierra Issue And Their Solutions
1. macOS Sierra Freezes or Crashes while Installing
If your Mac crashes or behave unresponsive while installing macOS Sierra, then do these few things to solve this macOS Sierra issue.
i. Before installing macOS Sierra, uninstall or disable any antivirus software on your Mac.
ii. Safe Boot your Mac and try reinstalling macOS Sierra. To load Mac in Safe Mode, press and hold the Shift key while it boots.
iii. It’s worth switching to a wired connection from a Wi-Fi before the download and install.
2. macOS Sierra issue: Not Enough Space to Install
While installing macOS Sierra, if you get error message saying you don’t have enough hard drive space, then you need to boot Mac in Safe Mode.
i. Turn off your Mac and wait for 10 seconds. To Safe Boot, press the power button and hold down the Shift key when you hear the startup tone.
ii. Release the Shift key when the grey Apple logo appears.
iii. In safe mode, delete the unnecessary files or move them to an external storage to free up some disk space.
iv. Now, restart your Mac and try reinstalling macOS Sierra.
3. macOS Sierra won’t start
After installing macOS Sierra, if your computer won’t start then restart it by holding down the Command, Option, P and R key. It will reset the NVRAM (non-volatile RAM) as well as the PRAM.

Hold these keys until the Mac restarts and you hear the second startup chime. Release the keys after the second startup chime.
4. macOS Sierra issue: Bluetooth devices not working
Some Mac users experienced issues while connecting their Bluetooth devices to the updated system.
Power-cycling (i.e. running your devices to zero power and charging them again) all devices, including the Mac, can solve this problem.
If this doesn’t solve your problem, then downgrade you Mac to El Capitan until the provider of Bluetooth device issues a firmware updated to support macOS Sierra.
5. Time Machine won’t Backup Mac
After upgrading to macOS Sierra, the Time Machine is restricting Mac users from backing up their devices. This problem is prevalent enough that Apple released a guide on what to do if you can’t back up.
Reset System Management Controller (SMC) for iMac:
i. Shut down the device.
ii. Disconnect the power cord from monitor.
iii. Wait for 1 minute.
iv. Reconnect power cord.
v. Do not power up the device.
PRAM Reset:
i. Shut down your Mac.
ii. Now, press and release the power button to turn on the Mac.
iii. Press and hold the Command-Option-P-R keys before the grey screen appears.
iv. Hold down the keys until your Mac restarts and you hear the startup sound for the 3rd time, then release the keys.
You can now try backing up your device. If that doesn’t work, try turning off indexing on the drive you’re backing up.
6. macOS Sierra issue: iTunes not working
If your iTunes is not working after the macOS Sierra upgrade, then update your iTunes to the latest version to solve the iTunes not working issue.
7. Mac overheats and fan keep spinning
After macOS Sierra upgrade, some users find that their Mac overheats or the fan keep spinning making the machine noisier.
If the fan keeps spinning, then stop Finder from indexing your hard drive. Open the Activity Monitor to see if Finder is indexing your hard drive.
If the fan is distracting a lot, then restore to previous version of Mac.
8. macOS Sierra issue: iCloud Errors
If you see iCloud error message saying there’s a problem authenticating iCloud, then open the Apple Menu and click on System Preferences. Select iCloud > Sign Out.
Now, reboot Mac, then go back to the iCloud and log back in.
9. Mouse not functioning properly
Some Mac users faced issues with their mouse after upgrading to macOS Sierra. It looks like most users are having trouble with mice made by Logitech and Razer.
You have to wait till these manufacturers release the suit related to updated macOS Sierra drivers.
For Example: Razer mice users can fix their issue by following the instruction below.
First, unplug your Razer mouse, then delete RazerHID.kext found in /Library/Extensions/RazerHID.kext.
Now, restart you Mac and the mouse will work properly.
Also, some of you may have noticed that plugging the mouse directly into Mac, rather than a wireless transmitter or USB hub can solve this issue.
10. macOS Sierra video problems and unusual color display
If your Mac display is behaving unusual, then you need to perform SMC reset.
SMC Reset for iMac:
i. Shut down the device.
ii. Disconnect the power cord from monitor.
iii. Wait for 1 minute.
iv. Reconnect power cord.
SMC Reset for MacBook with internal battery:
i. Shut down the device.
ii. Plug in the power adapter.
iii. Hold Shift + Control + Option and the Power button at the same time.
iv. Now, release the keys and you will see the light on power adapter will change color briefly.
v. Boot your MacBook normally.
As macOS Sierra is newly released, more issues may emerge and hopefully Apple is quick to release updates and fixes to fight these issues.
Still, make sure to check our blog section as we’ll be constantly updating any new macOS Sierra issue or problems.
Hope, the fixes above resolve your macOS Sierra issue.