OS X Sierra wifi/internet issues

"None of this software garbage works. Wifi on my 2012 iMac worked flawlessly before upgrading to Sierra. Now constant, "No internet connection." Obviously a flaw in the OS and when is Apple going to issue a fix? I tried all the software fixes listed and reset the PRAM and SMC, no effect. All my other Apple devices connect so don't tell me it is my router."

I can imagine that you are irritated. But if is is a "flaw in the OS" there should be hundreds of thousands or millions who have this: why not searching the Forum for all those messages, maybe you find solutions.

If this is not a general problem:

something in your settings is wrong, which I don't think, because the WiFi settings are not changed by upgrading to Sierra,

or there is a software on your mac that causes this: check all software on compatibility and isolate crap software like antivirus, keepers, cleaners, tumers, optimizers and so on.

So the same computer and the same router have worked flawlessly for 4 years and the only software I changed was the OS and now there is a software conflict? I have not added any new software other than the OS. If you want to see users with the same problem, Google, "Wifi connectivity problem after Sierra upgrade." This has been a problem since the beta version and yes it is thousands of users.

Yes, that is not uncommon, folllow my post "....or there is a software on your mac that causes this: check all software on compatibility and isolate crap software like antivirus, keepers, cleaners, tumers, optimizers and so on.".

You can also post an etrecheck list (see etrecheck.com) and we will give you advice. Even if you hacked this thread.

Cable modem is working correctly, wifi router is working correctly, my iPad, 3 iPhones, and my ancient MacBook running Lion all connect without problems. My Windows 10 laptop connects without problems. I don't think it is a hardware issue. This problem appeared on the first boot after upgrading and has been present since then.

Tried the 10.12.2 combo update to see if by chance I had a corrupt version of Sierra. No difference, same problem. I turned off wifi and hooked up an ethernet cable. That is working. Thanks Apple for ignoring and not solving a real problem.

Hi guys,

Let me add myself into this thread. I have a brand new MacBookPro 2016 that came with Sierra. The only issue is right the one described here: wifi stays connected, but every 3-5 minutes internet connection drops. El Capitan works just fine.

I've tried deleting prefs files, no change. I've tried the custom network set up (MTU), no change...

A few minutes ago, I thought about something: my FTTH Internet works fine. All my devices connect fine too. Maybe Sierra has a bug with mixed algorithms? In my case, I had WPA2 AES-TKIP. TKIP is old and unrecommended. So, for the sake of testing, I just switched to AES (which should be better).

I'll keep on checking the situation.

Hi everyone !

I'm kind of new to the Mac universe with a Macbook Pro 15" with TouchBar and while my experience is great... i've the same major problem with the wi-fi connection ! It's keep going on and off... without any reason. And, of course, no problem with my tablet, my phone and others PCs...

I've tried the different solutions found online but nothing has really worked. I'm sending this post using the pairing with my iPhone...

Do we know if Apple knows about this and has a "verified" solution ? Theses machine cost a lot... at least they could work !

(Sorry for my english, message from France 🙂)

Hi from Switzerland!

Please make sure your router is configured with wi-fi WPA2 AES. It seems Sierra has issues with mixed AES-TKIP.

That's what I've done. But the problem remain...

I had the same problem and tried all the suggested solutions here an in other tech threads. What solved it for me was to reboot in protected mode (hold down the shift-key while you reboot) and then reboot again in the normal way. This seems to clear the system cache or whatever. After the normal reboot I could re-connect to my network without any problem. Hope this helps.

...just to add: This solution can be found in this article http://osxdaily.com/2016/09/22/fix-wi-fi-problems-macos-sierra/ towards the end in part 3.

I've tried this. It worked fine during a few hours but, after going asleep et wake my MBP up, the problem reappeared.

I have the same problem now. Everything worked fine yesterday. Overnight I put my MacBook to sleep. On wake up this morning the problem reappeared and I can not connect to my Wlan network. I tried to reboot in protected mode and then a normal reboot but it does not help. Back to square one - how frustrating.

Have tried all the posted solutions without success. What bothers me is Apple assumes none of us have any computer experience and always blames the router. My router works with 5 other computers and multiple portable devices. I have set up my own routers since 1996 and have been using Macs since 1987. It is not a router problem. It is a software bug in Sierra that Apple won't fix because there are not enough complaints yet. Buy a really long ethernet cable and plug it into your computer. That works.

Hi, I'm using WPA2 AES but this issue is a nightmare. First, I thought it was AES-TKIP, then I switched to n/g protocol instead of 'auto'. Crap!