When exporting "Everything", the collections will be added as transform groups in the final .i3d file, referenceId property is not assigned for collections obviously so that caused a export fail.
Fixed by simple checking if the blender_object is not a collection before calling _add_reference_file.
When exporting "Everything", the collections will be added as transform groups in the final .i3d file, referenceId property is not assigned for collections obviously so that caused a export fail.
Fixed by simple checking if the blender_object is not a collection before calling _add_reference_file.