Quote from Hog_blast
My spruce planks aren't showing up and I can see through the ground, any reason for this?
Incase what Dante said doesn't help.. it sounds like the problem is to do with the game reading the textures as transparent; that colour being the pink you see in terrain.png. It is just very likely that your game is unpatched, or some corruption happened since even the oldest versions of any pack would still have dirt, stone, and grass textures meaning the ground would be visible. But again if that doesn't work; maybe that info will help you figure out what is the problem.