I've had my own modpack put together for quite awhile now, but I've waited until I'd bought an efficient computer in order to run Minecraft smoothly (I'm using MC 1.6.4, by the way)

I had fixed all compatibility issues with the mods months ago and there was never a problem starting the modpack up. I haven't added anything new, nor have I changed the config... the only difference is I'm using a different computer.

Any input on how to fix this issue would be greatly appreciated. I apologize if I posted this in the wrong section/category; I'm new to github.

Thanks.

Edit:
Issue solved.

Are you using BuildCraft 4.2.2? That version is unsupported, but you might be able to disable update checks in the BC config

Yes, I just edited the post and included that. My apologies.