[Gameplay] Mac OS X El Capitan secondary screen flickering

The Igor Guy·11/1/2015, 6:40:09 AM·5 votes·15,112 views

After upgrading to El Capitan if any external or secondary monitor are connected whenever the game starts (not the air client but the game proper) any elements (ie. a browser window, the menu bar or any other application) that are open and running on the external/secondary monitor start flickering and then after a little while fragmenting.

OS X El Capitan 10.11.1
MacBook Pro with Retina (mid 2012)
Thunderbolt to DisplayPort connections.

16 Comments

FreundinAmPC11/3/2015, 3:19:30 PM3 votes

Having the same issue. Connecting via HDMI.

racingSnail11/13/2015, 4:02:11 AM2 votes

same issue, please provide a fix asap. When the game runs in full screen mode, the secondary monitor flickers a lot. (not the entire screen, but part of it)

computer: Macbook Pro with Retina (mid 2012) OS: El Capitan 10.11.1 Setup: 2 external monitors connected with thunderbolt-display port and HDMI

RiotAjeckFira11/19/2015, 10:39:48 AM2 votes

Hey Guys! So I've seen this problem come and go for awhile. I first noticed it on Yosemite if you installed the Beta WebDrivers provided by nVidia. In El Capitan something has changed; I suspect the default drivers were updated. In any case, I've seen this occur on both OSX machines I use, my Macbook at work and Hackintosh at home. Both have nVidia cards, so I'm not quite sure if this occurs on other GPUs.

I don't work on the game, but I wanted to see if I could come up with at least a work around until the issue is fixed. Playing around with various settings in the game I've come to the following diagnosis:

The flickering happens when in full screen at max resolution
The flickering happens when in borderless mode at max resolution
The flickering didn't occur when setting the game to borderless mode with any resolution less than max.
If you go into the game config and set either the Height or Width resolution to 1 pixel less the game doesn't flicker.

Easy Work Around

Set your game to borderless mode and use the option that is right below your max resolution. i.e if your max resolution is 1920 x 1080, your next option may be 1600x900

Hard(er) Work Around (This will void your Teemo warranty)

Go to Applications, right click league and click "Show Package Contents"
Follow the Directory structure: Contents -> LoL -> Config
Open game.cfg in your favorite text editor (I used Visual Studio Code, yes they have that for OSX lel)
Under the [General] section you will see Height and Width settings.
Set one of the to 1 pixel less. i.e if your game is 1920x1080 setting it to 1919x1080 or 1920x1079 should work.

Both of these options worked for me and I hope this works for you until the proper fix is released.

Fowfow12/1/2015, 8:29:50 AM1 votes

fixed for me too for now, thanks. Was getting crazy already

pscL112/21/2015, 7:21:42 PM1 votes

Hey Guys... for now 10.11.2 update fixed this bug for me... great news to get rid of this annoying sh**... i was about to get used to it :-D