I cant load the modpacks i got with the technic launcher

[seb999000]

I have a mac version 10.6.8, and I have a problem with all of the modpacks I got that were preloaded onto the technic launcher. This doesnt happen with the modpacks i find on the site. I can run pixelmon because I found a pack for that on the technic launcher site. whenever i try to run a pack that came with the launcher it starts loading naturally, it brings me to a white blank window, it says that FML is building my minecraft environment and it closes unexpectedly. this bothers me alot because i really want to try games like tekkit and mostly hexxit. so can someone please tell me what im doing wrong or what is wrong with my computer?

[Kalbintion]

Post on the tracker, link at top of page, or in my signature below.