cant play modpacks

[OhElby]

when i try to play a modpack it loads the modpack then nothing happens and the technic launcher pops back up like when you close a modpack and i cant run any modpack, i already uninstalled and reinstalled and it still doesnt work. technic log ------> https://pastebin.com/Epx289Uk this is the most recent log i hope someone can help

[AetherPirate]

2017/08/17 05:04:10 [INFO]  # There is insufficient memory for the Java Runtime Environment to continue.

You are trying to allocate 5GB... how much memory does your PC have?