The plug-in does not support the following material types: Material with type 'unknown' will be imported as a Phong material

[Anonymous]

(If you have office hour, I'd be more than delighted to attend and get in-person virtual help).

I am new to Maya. I have a 3D model of an IKEA bed that has sheets, throw and else thing but I am only interested in the wooden bed. I was hoping to be able to import it into Maya (either of the fbx or obj files), and somehow remove the other stuff from the rendered bed and end up only with the wooden bed.

So my questions are:
1. Is it feasible and how should I remove these other layers on top of the bed? such as blanket or sheets?
2. Why am I getting the following error when trying to import the FBX file into Maya using import from file menu?
3. I plan to fill the holes in the IKEA bed but how can I automatically know where the holes are without manually inspecting it? I need to do step 3 as a preprocessing step to feed into TSDF fusion algorithm for watertighting the mesh of a 3D object. You can read more here: https://github.com/facebookresearch/phosa/issues/19

I have Maya student license.

The plug-in does not support the following material types:
Material with type 'unknown' will be imported as a Phong material.

Here are the textures used for various parts of this bed:

Here's how the bed looks like:

Here's the directory for the bed model I downloaded:

finally, here's the error screenshot upon importing the Ikea_bed.fbx file: