Quote Originally Posted by Pokemon-freak89 View Post
Okay, I decided to switch to MultiMC because it might actually keep working.

However, when I try to log in with it, it acts like I just started up VANILLA minecraft. The first time, it also had an error saying "the directory is not empty."

WhyTF would I WANT the directory empty?! How would it know what mods to use?!
You need to run it once as vanilla to install the new instance of minecraft, unless you are copying a .minecraft folder as an instance. Then you put in Forge and run it again to generate a mods folder. Then put the mods in.

As far as the whitescreen with MagicLauncher... sounds like a META-INF folder wasn't deleted.