[CLIENT] Only part of the screen shows

I wanted to report on a bug that I experience using my mac.

Even during the load screen, part of the screen is not shown. I am unable to even access and change the settings since the menu and item store are both unclickable.

Do you know how I can better address this issue? I tend to have to redownload the client, which is very cumbersome. After around 10 games, I received the same issue again.

Here is an image of the bug: http://imgur.com/a/F7a65