New Minecraft 1.6 Launcher doesn't work

Not working
I expected it to work and login to the game

The launcher didn't wanna open,it only opened the bootstrap,then closed.And sometimes it opens the launcher then closes.

Steps to Reproduce:
1.I opened minecraft.
2.Minecraft randomly closes unexpectedly.
3.Minecraft not working.

(Only happens if i try to get it with a mod,and hard to delete the mod from minecraft.)