HardwareMac & macOSNetwork

Instructions: Fix Wi-Fi issues on macOS Sierra

The brand new MacOS Sierra has been a disappointment for me so far. No, not because Siri on Mac utter nonsense (I already knew that from the iPad ;) ), but because it caused me a bunch of problems on my 2015 Macbook. So Sierra deleted during installation unasked two laboriously set up VPN accesses that I urgently need for work. Less dramatic, but at least as annoying: Since macOS Sierra, my Macbook has had massive WiFi problems. Sometimes it doesn't connect to the Fritzbox at all, then the connection breaks off again. And even if the WiFi is working, the WiFi icon in the menu bar doesn't stop blinking. Mega nerve ;) Luckily there is a solution for the WiFi problems of macOS Sierra. 

The solution is to reset your Mac's WiFi settings. By the way, you won't lose your previously saved network accesses (at least that's how it was for me). In any case, the steps described have led to stable WLAN access again on my Mac.

This is how you do it:

1. Open Finder and navigate to the folder

Open the Finder and use the keyboard shortcut Shift + CMD + G. In the input window that appears, enter the following folder name to call it up:



2. Backup and remove WiFi settings

In the folder that is now displayed, you must delete the following files. To be on the safe side, copy them to another folder or folder first. moves them. Here's how you can restore the settings if they don't fix your Wi-Fi problems under macOS Sierra:

  • apple. airport. preferences. plist
  • com.apple.wifi.message-tracer.plist
  • NetworkInterfaces. plist
  • preferences. plist
WiFi issues macOS Sierra
Delete these files to reset your WiFi configuration and troubleshoot problems

3. Restart Mac and hope for the best

Now restart your Mac and reconnect to the WLAN of your choice. Ideally, the WLAN errors should now be a thing of the past. If, contrary to expectations, it does not have the desired effect, you can of course restore the files you just deleted.


How do you feel about macOS Sierra? I don't really like the new features so far, but that could also be because I can't use most of the standard Apple applications (e.g. Safari and Email) not or only rarely use. Siri couldn't help me with my test questions either (especially since the web search via Bing is a cheek anyway ;) ) and otherwise I just had the problems described. Well, maybe it will be. In any case, none of this is running as smoothly as the excellent El Capitan.

By the way: The steps described not only work in Sierra, but also in older versions of macOS!

Boris Hofferbert

Freelance journalist, enthusiastic about technology since the blissful Amiga days, Apple desktop fan and Android fan on the go, gambles on Windows, can’t do without music (from classic rock to ska to punk) and audio books, likes to take postcard photos, always has at least two cell phones and is very happy about one coffee donation ;-)


  1. Deleting the 4 files helped me. Really perfect, thank you!!!
    What I don't understand, I bought about 100€ for cables (Thunderbold 3 to Thunderbold 2 and Thunderbold 2 cable) so that I can connect my iMac to my MBP.

    Then the wifi problems started. Apple knows well, but why do you offer this possibility, although these problems exist???

    I'm really close to saying goodbye to Apple. The costs for cables and the like alone have been annoying me for years. Apple is making it increasingly difficult to retain existing customers. Sorry for the blaming but that had to come out :-(

  2. It was too good to be true... :-(( After I deleted the specified files, restarted, connected to the WiFi and surfed... everything was wonderful. After what felt like half an hour it started again, the connection to the WiFi was lost again , just like before, it just took me longer to get back online PLEASE HELP!!!!

    1. Exactly the same here. After deleting the files and restarting everything works. With the next restart, the 5GHz connection of the MBP (Mid 2014, 10.13.6) only goes back to 20MBit, with the 200 line. Mobile phone (iPhone SE) makes 189 speed on the same AP.

      1. I was able to narrow it down now: If I delete the "com.apple.airport.preferences.plist" file and restart, the maximum speed is there again - until the restart. The file created does not differ in content from older files. I'll keep checking and changing the MTU size.

  3. THANKS SO MUCH ! ! !
    SUPER - TIP! ! ! !
    Worked great for me (Mac OS X 10.9.5). There is a lot of advice on the net about the problem, but unfortunately it didn't help. Now I'm happy that the permanent WiFi dropouts are a thing of the past

  4. OH wow it works again, you don't believe how grateful I am for the instructions ???? I was already despairing here why nothing works even though it is connected to the wifi ????
    Great tip, it worked great for me ????????
    Can I delete the copied data now?

    1. Thank you for the nice feedback, please recommend us ;)

      In general, you can delete the files when everything is running. I would tend to wait a few days to check if everything is really working, but I haven't come across any cases where this was the case :)

  5. Hallo,
    Thank you for these many helpful posts. Unfortunately there was nothing suitable for my problem here :-(
    I have a Fritzbox 7590 as well as a Fritz Repeater, which is located outside (garden) and at the point where the problems occur does not play along, or we already had the problems before purchasing the repeater.
    The problem itself only occurs with a 2016 MacBook Pro 13", the second MacBook of the same series (but 15") works perfectly, as well as all other WLAN devices (Windows PC, Windows laptop, vacuum robots, mobile phones, etc.) .
    The problem itself:
    The 13" Macbook had been having connection problems with the WLAN for some time -> the connection itself was not a problem, but it disconnected and reconnected every 5 minutes. This is practically not noticeable during normal surfing, since this process (Apple like) takes place extremely quickly. Furthermore, this is my partner's Macbook, so I don't always have an overview of everything and thought to myself that the problem no longer exists, since all the functions work without restrictions on all other devices & the lady no longer complained. However, when I took care of updates & Co again, I noticed that this is still the case, since it breaks off for a long time, for example, with the high Sierra update. I then tried everything I could think of, but I didn't get any successful results.
    I've tried: resetting the WLAN settings, deleting keychain WLAN passwords, deleting some relevant system preferences, PRAM/SMC reset, Fritzbox set up again & last but not least completely reinstalling the Macbook (Macintosh/SSD completely deleted). All data is specially backed up on the NAS, so I had no inhibitions here either, but I was faced with a problem: when restoring Sierra, it stopped for a long time due to the internet disconnection...
    What does that mean in my eyes? All possible settings on the MacBook have been reset/erased, but the problem still persists. All right, cell phone unpacked and created a hotspot. Look there, works. After a long time of further tinkering, I found out that the whole thing is on the 5Ghz band. 2,4Ghz range works. What could be the reason? I haven't had any other ideas for a long time.
    Here is a short clip about it: https://youtu.be/otORK9lg_c8
    Thank you for your replies and assistance
    Greetings Anton

  6. Thanks everyone for taking the trouble to provide solutions to the problems created by Apple. It works until the next interruption, which is less than half an hour away. I am now spending four weeks trying to get a 3000 EUR device to work, i.e. to switch off all the unnecessary crap. The internet connection fails me completely, I spend two hours a day trying to restore it. Unbelievable what Apple has come up with. It remains my last device from this pathetic brand, I simply feel fooled by Apple.

  7. Hello
    I've had this problem since today too. Unfortunately, your method only works for a few minutes. Then he throws me out again with my cell phone and MacBook Pro. I have deleted the lists several times now. It also keeps asking for the password, which I've already entered umpteen times...

      1. Signal is great! The connection is more stable on a cell phone (iPhone), but very poor on a Mac. Even a software update brought little. First yes, then the whole crap started all over again. With other PC's the reception is stable...

  8. I find the post a bit funny, especially the "Start again and hope for the best" But thanks for the interesting tutorial, I didn't know point 1 yet, you never stop learning.

  9. Great thank you. My internet is still super slow but now the wifi is finally staying connected. This improves my "user experience" immensely.
    So thanks :)

  10. Dear Boris, thank you for your article! Having moved house I didn't realize that my wifi problems were caused by the new system... After making desperate calls to O2 all day everything is working again!

  11. Colleague Hofferbert, you are my hero of the day! I worked with the WLAN assistant and speed port for three hours, and your suggestion then worked straight away. But OsSierra is also bizarre: under the WLAN icon in the upper tab, no more available networks were listed, not even my hotspot, and in the assistant I was able to call up my WLAN somehow, but it did not accept the password ("is wrong" ). Anyway, things are running smoothly now, so back to work.

  12. Hi, I bought a MacBook Pro last week, sierra is of course also installed... and now I also had the wifi problems described :-0 thank you very much for the super detailed description, in short, wifi is finally working...I hope it works like that remains. Many thanks for the help

  13. Why are you showing the entries (/Library/preferences/SystemConfiguration/) in English when the whole post is intended for German readers? So I can not find the folder. Makes no sense.

    1. Hello Titus,

      that makes a lot of sense ;) MacOS is a US system, so the internal system folder structure is in English everywhere in the world. Localization would simply not work for a number of reasons.

      You can check this quite easily: Open the Mac Finder and click on "Go" in the menu bar at the top while holding down the Shift, uh, shift key. MacOS then displays the "Library" folder, which contains the system files. So Apple didn't rename the thing "Library" or anything ;)

      As you can see from the comments here, a lot of people relate to this :)

  14. Hey guys, your great help has helped me several times. Thanks for that. Recently, however, the failures have gotten the upper hand. Do you happen to have any news on the subject? That would be amazing.

    Thanks and ahoy

  15. Thanks for your article! Just upgraded to 100.000 M/bits and was online slower than ever. But since my WiFi worked perfectly with my cell phone, it was clear that it had to be the Mac.

    Thanks to your article, everything is now OK again. You really helped me :)

    Thanks Marion

    1. So thank you very much, your recommendation has also solved the knot for me! Is an MBP 2015 and it still has El Capitan on it (router Fritz.Box).
      But I got a new Telekom connection and somehow have to reinstall the whole network fuss. Now it seems complete - great!
      ...and you can devote yourself to the important things in life again.

    1. A downgrade is only possible with a complete reinstallation or with a clean Time Machine backup of the status before the update. I wouldn't do it because it's a lot of work that doesn't make any sense at all.

      1. It can have many causes. In rare cases, the Mac and router may not be compatible. Or the WLAN settings are such that the Mac "gets it wrong", for example with some routers in dual-band operation. What router do you use, what Mac model do you have?

      2. So router: Fritzbox
        Model: MacBook Air early 2015. I think after the Mac turned off by itself, this error suddenly appeared, but I'm not sure. Before that everything worked fine.

  16. On my MacBookPro 2011, the 5GHz WiFi always cracks when the TimeMachine starts up, the slow 2.4GHz continues to run quietly. The above guidance has brought me nothing. /eom

  17. Thanks for the help, unfortunately it didn't work on my iMac. The result was that I could no longer establish a WiFi connection. Now I have reinserted the removed files and, as you can see, I can go online again.
    It's a pity that Apple creates such a shitty update, you're only used to that from Micro Soft. I hope this will remain an exception.

  18. Hallo,
    Well described instructions, which unfortunately didn't work for me. The PRAM and SMC reset didn't help me either.

    Router and MBP have been restarted several times, other devices can connect to the router without any problems. Any other suggestions?

  19. Hallo,

    wanted to report briefly: I carried out the tips last night (Macbook Pro from 2012). Haven't had any disconnections or other WiFi dropouts since then. Thanks a lot for this :)

    It's a shame what Apple put out there, I've never had as much trouble with an OS X update as with Sierra :(

  20. Thanks for the introduction. It didn't do anything for me. My iMac 2015 can't connect to my WiFi network. He recognizes it, but connecting is nothing...

      1. What is this (PRAM reset)?
        Sorry for the question, I'm not that savvy.
        I followed the instructions to fix the WiFi problem, but unfortunately it didn't help. I noticed that I don't have all the files you listed in the folder either.

Leave a Comment

Your e-mail address will not be published. Required fields are marked with * marked

This website uses Akismet to reduce spam. Learn more about how your comment data is processed.

Back to Top button


Please deactivate your ad blocker.