[mod packs not opening]

I've had this problem for a while now. Everytime I try to launch a mod pack the launcher goes away for a minute only to pop back up a few seconds later and nothing ever launches. I have it set to 3 GB for memory and I'm running on the latest Java.

Here's my logs: http://pastebin.com/w4NgtFeU

Thank you very much for any help!

​I am having this same exact problem! Please someone help us!