So, I updated my java to JRE version 1.7.0_09-b05, which disabled Apple's 1.6 version. Before i updated java, the error i would get was "exception.OutofMemory: no java heap space left" whenever i tried to load singleplayer world. AFTER I updated java, i would open the launcher just fine, then launch the Modded mc. A FML box appeared which validated the MC before it even loaded. Then the window for MC would pop up, then suddenly vanish, along with everything from the FTB Launcher, LEAVING NO CRASH LOG BEHIND. I can play regular MC just fine, but could someone please tell me how to fix this?