I have set an AR object Tracking session, inserted my license key, transformed my .fbz-file into an .obj file and also added the material file as extra file path. When I click play, and try to start the object tracking, it causes an error in unity stating: "Error: Error in opening OBJ file:" and "Error: invalid trackable". Both of these messages are generated twice each time i try to run it. I don't know what i am doing wrong and would be very grateful of some help.