Though ''Relative'' path seemed okay, FBX imported to PoserPro_11.3 at ~45% scaling, flat on face and minus textures. As the free model had a proper hierarchy {tick}, I was able to flip it upright without parenting swarm of parts to place-holder. I opened the PMX version kindly bundled {tick} in free PMX Editor, was able to cross-match and hand-load the 20 materials to their textures, plus reflection and normal maps.
After a test render in the default pose and saving to library, I very warily tried adjusting the stance. This is the point where Poser wrecks majority of imported FBX files. Not so Courtney !! {tick} I was able to save the pose, too. {tick} The morph / sliders for expressions, lip-synch etc worked. {tick}
IMHO, Courtney sets the standard for file conversions, with FBX complemented by PMX, plus Blend for tweaking. FWIW, I followed the rip credit, tracked down DemonBoy''s OBJ/MTL too...