Modpacks won't load

[Playyy]

Hello, i have a problem with loading modpacks.
So, when I click the "play" button it's loading but when it tries to launch it just goes back to the launcher. At first i had to install a 64 bit java to start with more ram (i chose 8GB out of my 16).
Here's my log:

http://pastebin.com/13JPpCn9

[AetherPirate]

See if this applies to you

And do not allocate more than 4GB

[Playyy]

It worked, thank you