Modpacks won't launch

[Dragon20558]

I've been trying to play with a group of friends on the Technic launcher attack of the b team, but every time i try to launch the mod pack, (pressing play) the Technic launcher disappears for a split second and reappears. i currently have the latest java installed-8 121, but I've tried the 7 ones and still don't work. i don't have a problem with my ram as its set to 2.5, I've rolled back my Nvidia driver, restarting my computer and nothing, i feel like I've tried everything please help!!! i just wanna play me some mine craft

just came up with this in the console, and this happens when tried to launch ftb but i gave up on that. Something about VM if you know how to fix that!

 [B#349]  Error occurred during initialization of VM
[B#349]  Initial heap size set to a larger value than the maximum heap size
[B#349]  Picked up _JAVA_OPTIONS: -Xmx256M
[B#349] Analytics Response [runModpack]: 200
[B#349] Starting download of http://cdn.technicpack.net/platform2/pack-icons/552556.png?1445088955, with 3 tries remaining

Edited March 14, 2017 by Dragon20558

[TheLastSpectre]

I believe Attack of the B Team has a minimum requirement of 4 gigs of RAM. Some other packs require less, however AotBT is a big modpack. Try setting it to 4 gigs and see if that works.