Modpack crashing

[_Love_Ranked_]

So basically whenever i launch a modpack by clicking the play button, it does its magic, starts the loading bar and when the bar finishes and the game SHOULD start, instead the client just comes back with the play button, what do i do? here are my logs:

<snip> use pastebin or attach the log file. - LP

[JaariAtmc]

Something about an extracted mod jar, and the last one is saying that it tried to use 4 GB but it wasn't available. I Hate Users that dump their whole log.