I'm getting a blocky/zig zag texture has anyone seen this before?

I textured this character in substance painter. and it looks great in every other package. but when I load this into the material it looks broken. All the other materials work fine this is really strange. Has anyone seen this type of issue before?

Thanks in advance.

Rob

Are you importing the texture as a normal texture or a virtual texture? (Does it have a small VT in the texture?)