Q: OSX Yosemite Wifi issues

Sorry!!, ok, this worked for me, so you can try it if you want;

Turn off your wifi, go to finder and press COMMAND - SHIFT - G, and then type /Library/Preferences/SystemConfiguration (Caps are important according to the advisor) and then press enter.

Inside the window, look for NetworkInterfaces.plist. (Delete), and then Preferences.plist. (also delete).

Go to the apple icon on the bar and reset your mac.

You should have wifi after restarting.

Good luck!!

The deleting of network preferences solution only works for a short while, the problem comes back after a reboot or when woken from sleep - or at least it did in my case (and from reading this thread quite a lot of other people as well)

Has everybody who's got this issue filed a rug report with Apple, giving them all the info they need, such as Wireless Diagnostics output

"Please option-click the WiFi Menu Extra and choose Wireless Diagnostics. It will offer to run until detecting a problem. When the link drops, it should create a file on the desktop. Please attach that file to the report."

Ok, i tried rebooting as you said, actually rebooted 3 times and my wifi is normal. I also put my mac to sleep and when i opened it my wifi was normal.

I've been working for several hours with no interruption. Maybe is just a matter of luck as that guy said a few posts back.

Sorry in advance for my bad english...

try this

1. turn off your mac book.

2. connect the power source

3. press and hold at the same time left side SHIFT CONTROL OPTION and POWER for 5 seconds

4. RELASE ALL BUTTONS AT THE SAME TIME

5. finaly turn on your mac book

This procedure fixed my wi-fi from connect and disconnect  

The problem is, all these solution may temporarily fix the problem with the WiFi, but after a couple of reboots the problem comes back.

What we really need is an official fix from Apple.

You lose internet connection if you try to connect to a https:// site.

After that even http:// isn't working anymore

Problem is solved for me by stoping parenting control for all users and make them administrator. 

Its a work around waiting till the fix

I dont have parent control. still i continue to have wifi drop. every 3-5 min, it drops and i have to restart the system. I also noticed that all apps works fine like Viber, Skype, FaceTime. but i am not able to browse any page through safari or chrome.

Security researchers at Sophos have a post about this along with a shell script that might help some folks with this until Apple fixes this issue. The article is here: http://nakedsecurity.sophos.com/2014/10/22/os-x-yosemite-wi-fi-problems-can-you- help-us-solve-them/

this didn't work for me. Another failed 'fix', in my experience. Boo on Apple.

I had this problem too. I tried everything that I found on internet, the solution for me was to come back to Maverick (OS X 10.9).

The Three Laws are perfect. Thanks!

OK. I did this (on a 2012 Mac Mini) and my wifi connection has been strong and stable for an extended time. Maybe it actually fixed the problem; time will tell ----

MacDailyNews Take: This is not a new issue. It also happened with OS X Mavericks. We had this problem on one of our Macs running OS X Yosemite and fixed it the way we always have, by resetting the SMC (System Management Controller).

We don’t know precisely why this works, only that it has worked for us in multiple cases of wonky Wi-Fi with iMacs and MacBook Airs running OS X Mavericks and OS X Yosemite.

Resetting the System Management Controller (SMC)

Resetting the SMC on portables with built-in batteries:
1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.

Resetting the SMC on Mac portables with a battery you can remove:
1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it’s connected.
3. Remove the battery.
4. Press and hold the power button for 5 seconds.
5. Release the power button.
6. Reconnect the battery and MagSafe power adapter.
7. Press the power button to turn on the computer.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve:
1. Shut down the computer.
2. Unplug the computer’s power cord.
3. Wait fifteen seconds.
4. Attach the computer’s power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Note: Resetting the SMC does not reset, or otherwise change, the contents of PRAM, which is also known as NVRAM on Intel-based Macs.

I also have this issue and have tried the different suggestions. It kicks me off all the time and when it does work it is extremely slow. Today is the day my warranty runs out and support wasn't any help. Hoping this is fixed soon as my job depends on reliable wifi access.

This issue is only happening to me on my Macbook Air late 2010 running OSX Yosemite..its constantly losing the wifi connection..the connection doesnt last a minute sometimes..the longest i've had it without disconnecting is 5 minutes... I have to keep turning the wifi on and off to get the connection back, sometimes its asked me for the password then says password invalid...so it turn it off again and hope it connects. I have tried all the solutions on this page and nothing has worked!!

I have a Macbook Pro 2.3 GHz running OSX Yosemite 15' late 2012 and its fine thanks god I'm lucky I have both Mac's otherwise my business would def suffer as I rely on the internet for my work!! This needs sorting APPLE asap!!

Same behavior on my MacBook Air. I've a Macbook Pro with Lion behind the Air connected at same access point and there's not any issue.

Looks like something is wrong with Yosemite and WiFi.

Is it possible to downgrade???

Working has becoming a nightmare!!!!