When I import a model into unity and apply the texture the models get weird lines and smudges on them, but these aren’t visible when i apply the texture in 3DS Max.
Any idea what is causing these issues it is on most of my character models.
Most likely business can be in settings of export of a texture in Unity. Try to set that your texture was without compression. At me too such was - two textures of diffuse and normal. Also there were black lines. After I set import without compression (32bit) for texture normal, everything was removed.