Modpacks just close.

[Kiryion]

After some time playing some modpacks, or even just after opening them they close and go back to the launcher, I don't understand what's happening, but I cant play like this

 

Edited April 10, 2016 by Kiryion

[FrostyZaij]

Might be your RAM amount? How much do you allocated? (Most packs will work with 2 GB of ram if they don't say that they need more)

[JaariAtmc]

Could be any of the following usual things (yours *might* be unusual, but can't tell without launcher logs):

• You have an interfering Java_Options environment variable that limits your Java processes to 256/512/1024 MB max.
• You have recently updated to Windows 10 and you only have an Intel HD graphics driver in your pc.
• A config file may have been corrupted.
• You may not be allocating enough RAM, or you are allocating way too much RAM.

So yeah, those are the ones I can think of right now, and there are more possibilities, therefore -> upload the contents of your launcher log to paste.ubuntu.com and give us the link.