Print Media CKeditor images correctly custom code
Problem solved.

$black_box_with_image_description = isset($content['settings']['black_box_with_image_description']['value']) ? $content['settings']['black_box_with_image_description']['value'] : '';
if (isset($content['settings']['black_box_with_image_description']['format'])) {
    $black_box_with_image_description = check_markup($black_box_with_image_description, $content['settings']['black_box_with_image_description']['format']);
}