FAQ:
Q: Minecraft crash on startup!? A: Goto Launcher Options->Java Settings then change the amount of Memory to at least 4GB.
Q: Modsorting problem when launching minecraft. A: Goto Modpack Options and click "Reinstall Pack" it will now reinstall using the cached version you have.
Q: Minecraft wont update, how can I force it? A: Goto Modpack Options and click "Open", then find the folder called "cache" and delete it. A2: If the first didn't help then close the launcher and open it again.