struktur pivot table antara PERTANYAAN dengan TAG

1 pertanyaan bisa lebih 1 tag, begitu juga sebaliknya

struktur pivot table saya kek gini

Schema::create('question_tag', function (Blueprint $table) {
            $table->integer('id_question')->unsigned()->index();
            $table->integer('id_tag')->unsigned()->index();
            $table->timestamps();

            // set primary
            $table->primary(['id_question', 'id_tag']);

            //set foreign
            $table->foreign('id_question')
                  ->references('id')
                  ->on('questions')
                  ->onDelete('cascade')
                  ->onUpdate('cascade');
            $table->foreign('id_tag')
                  ->references('id')
                  ->on('tags')
                  ->onDelete('cascade')
                  ->onUpdate('cascade');
        });

tapi pas saya insert / update ada error SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`forum`.`question_tag`, CONSTRAINT `question_tag_id_tag_foreign` FOREIGN KEY (`id_tag`) REFERENCES `tags` (`id`) ON DELETE CASCADE ON UPDATE CASCADE) (SQL: insert into `question_tag` (`id_question`, `id_tag`) values (1, 0), (1, 1), (1, 4), (1, 6))

keknya erornya di struktur pivot tablenya deh, apa saya harus ganti cascadenya..?