Seem to be getting unsupported type MaterialInstanceConstant, but the odd thing is the viewer can see it fine =/
MaterialInstanceConstant is supported (partially) in a viewer, but it is not exportable - there is no resource type for
shaders availabe (GLSL/HLSL/Cg shaders ?).
I'm looked at your log.
Textures are exported. You should detect roles of these textures (diffuse/normal/self-illumination etc for all model surfaces).
The following information may help you with such detection.
1) in
mesh viewer use <M> (as in your 1st screenshot) to get material names for each mesh surface
2) use PgUp/PgDn to browse all loaded objects, find each material (to allow browsing materials you should not use "-meshes" switch)
3) for each found
material, press <M> key - you'll see material internal structure (material parameters); by reading these values you may understand roles of all textures