pink and black textures

This has probably been answered before but i cant find it anywhere. I downloaded a skin pack for gmod and i installed them, but some of the the skinks look great and others are just pink and black checkers. Anyway to fix this?

Give us the link.

Do you have css?

yup i have css and hl2. and what link?

The link to the damn download. What else?

Also say what games you have?