I wrote a script. I one part of the script, there is this line: `base_object.data.materials.append (changeable_material)` whenever I try to run the script, blender just shuts down, immediately, without any error or anything, within a fraction of a second. base object is cube generated by the script, changeable material is precreated material. I don't have much experience with blender scripting. Is this mistake in my code or a bug? If not a bug, how do I fix it?