I had the version where there were Assets0-3.fpk. I unpacked them, but messed one up. So I reinstalled, and this time I got Art0 and Assets0. I unpacked them to the Assets folder this time, and now my graphics are all messed up. Also, I can't convert some of the .dds files anymore. 
I used these programs:
PakBuild
Converter

I used these programs:
PakBuild
Converter