Yosemite (OS X 10.10) killed my WiFi :(

After installing Yosemite my 2012 MBP will no longer recognize 5G networks from any routers.

...I've also reset the PRAM per other's instructions here (Command-Option-P-R on boot) and didn't fix the issue either :-P

This didn't work for me.

I've reset PRAM, removed SystemConfiguration folder, disabled bluetooth, removed all of my network configuration, reset my keychain, and still.... NOTHING. It works for about 15 to 30 seconds then just stops passing any traffic...

Are you on a WPA2-Enterprise network?

Giving that a try, nothing else has worked thus far.

What I've done was:

- Gone into Sys Prefs --> Network. Created a new location called Home.

- Went into Advanced --> Wi-Fi and removed all of my saved networks.

- Clicked OK then Apply.

- Turned off Wi-Fi then turned it back on. Selected my home WiFi and input the password.

Wish me luck!

WPA2 Personal... AES Only.

Even more odd... works just fine with my 802.11 b/g/n MikroTik routers WIFI.... it doesn't like the AC on my Netgear R7000.

Yosemite destroyed my wi-fi too. IMO jump-the-shark stupid by Apple!!! What is more basic than wi-fi!?! It's insulting to have to try several nerd solutions to restore it!!! CORRECT IT APPLE!!!

Same here. MBP retina mid 2012 with 802.11n adapter connected to 802.11ac router. 5Ghz barely works, 2.4Ghz works just fine.

I've tried to boot up machine with Ubuntu Linux, wi-fi works like a charm on both frequencies.

Does anybody tried to escalate this with Apple?

This did not help even the Mac tech support. However, deleting the folder /Library/Preferences/SystemConfiguration and the wifi never drops until you reboot. Once you reboot, you get Yosemitied!

Apple, my love please fix this issue. Wifi dropping 2 times or more every 3 minutes is not good!

I volunteer for testing.

Guys, I have a Macbook 2008 Unibody, upgrading to Yosemite killed my wifi too. Cannot turn it on at all, and it was stuck "off".

None of the solutions so far in thread worked (clearing PRAM, deleting configuration folders etc. Did nothing).

But I fixed it, heres how:

1. Open Network Preferences, click once on the WiFi adapter in the list there on the left. Then click the little cog icon at the bottom and select "Make Service Inactive". Click APPLY.

2. Then click on the WiFi in the same list there again, and then click the - button to delete it. Click APPLY.

3. Reboot the Mac.

4. Once rebooted, go back into the Network Prefs, and under the network adapter list click the + button, and then in the dropdown list (which is probably showing Bluetooth by default) select WiFi. For the name field, change it from WiFi to WiFi2. It's important you add something to the name here (I've just suggested to add a number 2), or else it will break again on next reboot. Click APPLY.

You should then have a working WiFi, that survives reboots.

GalagBasha's solution worked perfectly for my 2013 MacBook Air 11".

This finally solved issue on my Macbook pro mid 2009. Thanks a lot JamieAscot!

Thanks this seems to have worked - did not bother with deleting the Network service just made it inactive, duplicated it and made the new one active rebooted and all seems ok, gust got to see what happens when comes awake from sleep!