you said you put them all in a big compressed folder right?, so take all the trucks out of that folder and put them in the packs folder so then theres nothing in the "big compressed "folder then try.
I dont know if this has already been made; if it has been im sorry.
http://imgur.com/a/Hn0
http://imgur.com/a/0TjI8
i know its probably not going to be taken into consideration but i thought i'd atleast try.