Invisible textures after exporting from blender

Hi i’m new to JMonkey, whenever I export my mesh from blender some of the textures are invisible. Some show up fine without a problem but the ones that don’t you can see through them. It seems to be affecting the textures inside the mesh but I still need those to render.

https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:external:blender