I'm relatively new to Shapeways and I'm trying to upload my first full color sandstone model from blender in X3D, but I get the following error message: "It seems your product is missing the textures it needs to be 3D printed. Please check the uploaded file to make sure the texture is in the root directory." Now, in the blender file, the materials all have the needed textures taken from a single folder, wherein I also save the export. I zipped them all together (no not the outer folder, just the textures and export like I'm supposed to) but I always get the error message. As far as I can tell, the file names should be a perfect match and contain no folder titles or anything. I don't know what I'm doing wrong. I'd greatly appreciate any assistance.