OBJs MTL failed, no

On OBJ and MTL import i get black texture in game..

How do i fix MTL for MCreator to be able to read it?

ERROR:

OBJLoader.MaterialLibrary: key 'illum' (model: 'test_mod:models/item/test16x16cube.mtl') is not currently supported, skipping
OBJModel: A color has already been defined for material 'lambert2SG' in 'test_mod:models/item/test16x16cube.mtl'. The color defined by key 'Ka' will not be applied!
OBJLoader.MaterialLibrary: key 'Tf' (model: 'test_mod:models/item/test16x16cube.mtl') is not currently supported, skipping
OBJLoader.MaterialLibrary: key 'Ni' (model: 'test_mod:models/item/test16x16cube.mtl') is not currently supported, skipping
 

MTL:

newmtl lambert2SG
illum 4
Kd 0.00 0.00 0.00
Ka 0.00 0.00 0.00
Tf 1.00 1.00 1.00
map_Kd redgrass.png
Ni 1.00

Thanks!