iNeedMyTurrets

Hello, i had problems when i was using 32bit java on my technic launcher, so i downloaded 64bit java but when i want play modpack now, it says checking minecraft assets, then there is moment when the modpack should start but instead of it the technic launcher shows again without any error report. i dont really understand these java versions and that, but the 32bit java was 1.8 and this 64bit java is 1.7 but it says its max updated. please help me somehow this screenshot may help someone who wants to help me