Problem with nUI textures being all white
 

I love nUI but I can't use it because the textures around the manabars etc are solid white blocks, to include the HUD. I downloaded nUI+ from where I was told to download it in the email, and nUI regular did not do this but I need the 25/40 man raid version.

This is discussed in the F.A.Q. here, and is a known Blizzard bug.

If that's not the same issue you are having... updating your video card drivers should fix the problem.