See community discussion https://community.oracle.com/message/12383076

Using id in lookup on table should find the TableColumn. I dumped out the node structure of the table and the TableColumn didn't have the id.

    @Override
    public void start(Stage stage) {
        TableColumn<Fruit, String> fruitNameCol = new TableColumn<>(
                "Fruit"
        );
        fruitNameCol.setCellValueFactory(
                new PropertyValueFactory<>(
                        "name"
                )
        );
        fruitNameCol.setId("column-not-found");
        TableView<Fruit> table = new TableView<>(
                FXCollections.<Fruit>observableArrayList(
                        new Fruit("apple"),
                        new Fruit("orange")
                )
        );
        table.getColumns().setAll(
                fruitNameCol
        );
        stage.setScene(
                new Scene(
                        table, 50, 100
                )
        );
        stage.show();
        System.out.println("Found column => " + table.lookup("column-not-found"));
    }
    public class Fruit {
        private String name;
        public Fruit(String name) { this.name = name; }
        public String getName() { return name; }
        public void setName(String name) { this.name = name; }
    }