The FileChooserBuilder.SelectionApprover approve method is always called with an empty File[] array that makes no approving possible.

        File any = new FileChooserBuilder("openFilePreference")
                .setTitle("Fails to select any file"))
                .setSelectionApprover(new FileChooserBuilder.SelectionApprover() {
                    @Override
                    public boolean approve(File[] selection) {
                        return selection.length != 0;
                    }

                }).setApproveText("Open").showOpenDialog();