Add buildnings to 3d model


I have made an 3d model from a aeria. Now I need to export this 3d model to another program so I can add an building for a client. But I only can get the files in .MTL and .OBJ

The objekt file is fine, but the .mtl (texture) will not open in any program (Sketchup, Unity, 3d builder)

Is there any one have the same issue?

You might have to adjust the import settings to get them to work.
Or you might have to convert it in an interim program like Meshlab (free) or Blender (free). Bring it into one of those as an .obj file and export it and see if that imports better into your program.