Currently working fine with weapons (Enhanced Pack). Probably the same with other assets.
When you assign maps to your model in your model editor, use a dummy .png which does
not have the shader suffix.
example:
Texture with "texname1.png" and "texname2.png" and export with those maps assigned.
Be sure to use only one material per mesh object.
Save out your maps as:
"texname1_color.dds", "texname2_color.dds", etc.
From what I've been told, .png gets parsed from .x faster than .dds so that is why the dummy is a .png in my example.
Leave textured field blank in FPE.
While you may get lucky and have it load maps without assigning ones named in this manner, the method laid out above should reduce chance of error.
Gigabyte P67A-UD4-B3, Intel Core i7 2600K (passmark 8555), 16GB Corsair DDR3, EVGA GTX 970 SC (passmark 8637), Win10 Pro 64-bit, Primary monitor @ 1920x1080, secondary monitor @ 1280x1024