Alright so here is exactly what I happened:
My friend made me a header image for my default wordpress theme. I already changed the default theme, so I decided to duplicate it. All I did was change the header image.
So my themes were
Cosmo Girl (same as default, but with a different header image)
+ other themes
Once that happened, it said "The active theme is broken. Reverting to the default theme." I assumed it was because of my new theme, so I deleted it. But it still said the themes were broken. So I deleted ALL of the themes. With NO themes at all, it still said "The active theme is broken. Reverting to the default theme."
Keep in mind didn't touch a THING.
oh yea, and at one point it said I needed a stylesheet and template for my theme. But I did have a stylesheet, and i don't know what it means by template. If it's something like template.php i've never had that before.
Any ideas? Please