Iwasjustlikeaaahellnawww

Every time i try to download big dig, a bar appears that says 0% in after a second or so the bar dissapears, this also happens with other modpacks like Hexxit, Tekkit lite and hack/mine. I would apriciate some help. Sorry for my english.

I did the steps put the optifine 1.4.6 into the modpack.jar i opened tekkit lite and it worked totaly fine but when i tried to make a new world it just sais: building terrain I left my computer for a couple of hours and when i came back it was just the same screen this also happens when i open a old world that worked without optifine. If i try cliccing on the screen it evantually sair Tekkitlite does not respond! Please help that'd be great :)