grayscale_new

footer.html.twig

            <div class="col-sm-6">
                {% if content.footer_menu_block is defined and
                    content.footer_menu_block is not empty
                %}
                    {% set footer_menu_items = content.footer_menu_block %}

                    <ul class="list-inline quicklinks" property="footer_menu_block" typeof="collection">
                        {% for menu_item in  content.footer_menu_block %}
                            <li class="list-inline-item" rel="footer_menu_block" typeof="menu_item">
                                <a href="{{ menu_item.menu_link }}" data-toggle="modal" property="menu_title">
                                    {{ menu_item.menu_title }}
                                </a>
                            </li>
                        {% endfor %}
                    </ul>
                {% endif %}
            </div>

grayscale_new.xml

<?xml version="1.0" ?>
<template xmlns="http://schemas.sulu.io/template/template"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://schemas.sulu.io/template/template http://schemas.sulu.io/template/template-1.0.xsd">

    <key>grayscale_new</key>

    <view>templates/grayscale_new/grayscale</view>
    <!--<controller>SuluWebsiteBundle:Default:index</controller>-->
    <controller>ExampleCustomBundle:Default:index</controller>
    <cacheLifetime>1</cacheLifetime>

    <meta>
        <title lang="en">Grayscale new</title>
        <title lang="de">Grayscale new</title>
    </meta>

    <properties>
        <section name="highlight">
            <properties>
                <property name="title" type="text_line" mandatory="true">
                    <meta>
                        <title lang="en">Title</title>
                        <title lang="de">Titel</title>
                    </meta>
                    <params>
                        <param name="headline" value="true"/>
                    </params>

                    <tag name="sulu.rlp.part"/>
                </property>

                <property name="url" type="resource_locator" mandatory="true">
                    <meta>
                        <title lang="en">Resourcelocator</title>
                        <title lang="de">Adresse</title>
                    </meta>

                    <tag name="sulu.rlp"/>
                </property>
            </properties>
        </section>

    </properties>


    <properties>
        <section name="Set page user and password">
            <properties>
                <property name="page_user" type="text_line" colspan="6">
                    <meta>
                        <title lang="en">Page user</title>
                    </meta>
                </property>
                <property name="page_password" type="text_line" colspan="6">
                    <meta>
                        <title lang="en">Page password</title>
                    </meta>
                </property>
            </properties>
        </section>
    </properties>


    <properties>
        <property name="site_logo_as_text" type="text_line">
            <meta>
                <title lang="en">Grayscale: Logo</title>
                <title lang="de">Grayscale: Logo</title>
            </meta>
        </property>

        <section name="Header menu details">
            <properties>
                <property name="header_menu_small_device_label" type="text_line">
                    <meta>
                        <title lang="de">Header small device menu label</title>
                        <title lang="en">Header small device menu label</title>
                    </meta>
                </property>

                <block name="header_menu_block" default-type="editor" minOccurs="0">
                    <meta>
                        <title lang="de">Header menu title and link</title>
                        <title lang="en">Header menu title and link</title>
                    </meta>
                    <types>
                        <type name="header_menu_details">
                            <properties>
                                <property name="menu_title" type="text_line" colspan="3">
                                    <meta>
                                        <title lang="de">Menu name</title>
                                        <title lang="en">Menu name</title>
                                    </meta>
                                </property>
                                <property name="menu_link" type="text_line" colspan="9">
                                    <meta>
                                        <title lang="de">Menu link</title>
                                        <title lang="en">Menu link</title>
                                    </meta>
                                </property>
                            </properties>
                        </type>
                    </types>
                </block>
            </properties>
        </section>

        <property name="top_background_image" type="media_selection">
            <meta>
                <title lang="de">Top background image</title>
                <title lang="en">Top background image</title>
            </meta>
        </property>
    </properties>

    <properties>

        <section name="Welcome detail">
            <properties>
                <property name="welcome_data_description" type="text_line" colspan="6">
                    <meta>
                        <title lang="en">Description </title>
                        <title lang="de">Description </title>
                    </meta>
                </property>

                <property name="welcome_data_button_label" type="text_line" colspan="6">
                    <meta>
                        <title lang="en"> Button label </title>
                        <title lang="de">Button label </title>
                    </meta>
                </property>


                <property name="welcome_data_text" type="text_editor">
                    <meta>
                        <title lang="en">Welcome text</title>
                        <title lang="de">Welcome text</title>
                    </meta>
                </property>

                <property name="welcome_html" type="text_editor">
                    <meta>
                        <title lang="en">Welcome html</title>
                        <title lang="de">Welcome html</title>
                    </meta>
                </property>
            </properties>
        </section>

        <section name="About detail">
            <properties>
                <property name="about_title" type="text_line">
                    <meta>
                        <title lang="en">Title</title>
                        <title lang="de">Title</title>
                    </meta>
                </property>

                <property name="about_description" type="text_editor">
                    <meta>
                        <title lang="en">Description</title>
                        <title lang="de">Description</title>
                    </meta>
                </property>
            </properties>
        </section>

        <section name="Download data">
            <properties>
                <property name="download_title" type="text_line" colspan="3">
                    <meta>
                        <title lang="en">Title</title>
                        <title lang="de">Title</title>
                    </meta>
                </property>
                <property name="download_link_text" type="text_line" colspan="3">
                    <meta>
                        <title lang="en">Link text</title>
                        <title lang="de">Link text</title>
                    </meta>
                </property>
                <property name="download_url" type="text_line" colspan="5">
                    <meta>
                        <title lang="en">Url</title>
                        <title lang="de">Url</title>
                    </meta>
                </property>
                <property name="download_description" type="text_editor">
                    <meta>
                        <title lang="en">Description</title>
                        <title lang="de">Description</title>
                    </meta>
                </property>
                <property name="download_background_image" type="media_selection">
                    <meta>
                        <title lang="de"> Download Background image</title>
                        <title lang="en"> Download Background image</title>
                    </meta>
                </property>
            </properties>
        </section>

        <section name="Accordian block">
            <properties>
                <property name="accordian_title" type="text_line">
                    <meta>
                        <title lang="en">Title</title>
                        <title lang="de">Title</title>
                    </meta>
                </property>

                <property name="accordian_sub_title" type="text_line">
                    <meta>
                        <title lang="en">Sub title</title>
                        <title lang="de">Sub title</title>
                    </meta>
                </property>

                <block name="accordian_first_block" default-type="editor" minOccurs="0">
                    <meta>
                        <title lang="de">Accordian First column data</title>
                        <title lang="en">Accordian First column data</title>
                    </meta>
                    <types>
                        <type name="first_column">
                            <properties>
                                <property name="title" type="text_line">
                                    <meta>
                                        <title lang="de">Title</title>
                                        <title lang="en">Title</title>
                                    </meta>
                                </property>
                                <property name="description" type="text_editor">
                                    <meta>
                                        <title lang="de">Description</title>
                                        <title lang="en">Description</title>
                                    </meta>
                                </property>
                            </properties>
                        </type>
                    </types>
                </block>

                <block name="accordian_second_block" default-type="editor" minOccurs="0">
                    <meta>
                        <title lang="de">Accordian Second column data</title>
                        <title lang="en">Accordian Second column data</title>
                    </meta>
                    <types>
                        <type name="second_column">
                            <properties>
                                <property name="title" type="text_line">
                                    <meta>
                                        <title lang="de">Title</title>
                                        <title lang="en">Title</title>
                                    </meta>
                                </property>
                                <property name="description" type="text_editor">
                                    <meta>
                                        <title lang="de">Description</title>
                                        <title lang="en">Description</title>
                                    </meta>
                                </property>
                            </properties>
                        </type>
                    </types>
                </block>

                <block name="accordian_third_block" default-type="editor" minOccurs="0">
                    <meta>
                        <title lang="de">Accordian Third column data</title>
                        <title lang="de">Accordian Third column data</title>
                    </meta>
                    <types>
                        <type name="third_column">
                            <properties>
                                <property name="title" type="text_line">
                                    <meta>
                                        <title lang="de">Title</title>
                                        <title lang="en">Title</title>
                                    </meta>
                                </property>
                                <property name="description" type="text_editor">
                                    <meta>
                                        <title lang="de">Description</title>
                                        <title lang="en">Description</title>
                                    </meta>
                                </property>
                            </properties>
                        </type>
                    </types>
                </block>

                <property name="accordian_background_image" type="media_selection">
                    <meta>
                        <title lang="de">Accordian background image</title>
                        <title lang="en">Accordian background image</title>
                    </meta>
                </property>
            </properties>
        </section>

        <section name="Contact block">
            <properties>
                <property name="contact_title" type="text_line">
                    <meta>
                        <title lang="en">Contact title</title>
                    </meta>
                </property>

                <property name="contact_description" type="text_editor">
                    <meta>
                        <title lang="de">Description</title>
                        <title lang="en">Description</title>
                    </meta>
                </property>

                <property name="social_twitter_link" type="text_line" colspan="4">
                    <meta>
                        <title lang="de">Twitter link</title>
                        <title lang="en">Twitter</title>
                    </meta>
                </property>
                <property name="social_github_link" type="text_line" colspan="4">
                    <meta>
                        <title lang="de">Github link</title>
                        <title lang="en">Github link</title>
                    </meta>
                </property>
                <property name="social_google_plus_link" type="text_line" colspan="4">
                    <meta>
                        <title lang="de">Google plus</title>
                        <title lang="en">Google plus</title>
                    </meta>
                </property>
                <property name="contact_office_detail" type="text_editor">
                    <meta>
                        <title lang="de">Office detail</title>
                        <title lang="en">Office detail</title>
                    </meta>
                </property>
            </properties>
        </section>

        <property name="google_embed_map_url" type="text_line">
            <meta>
                <title lang="en">Google Map Embed Url</title>
                <title lang="en">Google Map Embed Url</title>
            </meta>
        </property>

        <section name="Footer menu">
            <properties>
                <block name="footer_menu_block" default-type="editor" minOccurs="0">
                    <meta>
                        <title lang="de">Footer menu title and link</title>
                        <title lang="en">Footer menu title and link</title>
                    </meta>
                    <types>
                        <type name="footer_menu_details">
                            <properties>
                                <property name="menu_title" type="text_line">
                                    <meta>
                                        <title lang="de">Menu name</title>
                                        <title lang="en">Menu name</title>
                                    </meta>
                                </property>
                                <property name="menu_link" type="text_line">
                                    <meta>
                                        <title lang="de">Menu link</title>
                                        <title lang="en">Menu link</title>
                                    </meta>
                                </property>
                                <property name="popup_menu_title" type="text_line">
                                    <meta>
                                        <title lang="de">Popup Menu title</title>
                                        <title lang="en">Popup Menu title</title>
                                    </meta>
                                </property>
                                <property name="popup_menu_description" type="text_editor">
                                    <meta>
                                        <title lang="de">Popup Menu Description</title>
                                        <title lang="en">Popup Menu Description</title>
                                    </meta>
                                </property>
                                <property name="popup_menu_button_title" type="text_line">
                                    <meta>
                                        <title lang="de">Popup Menu Button title</title>
                                        <title lang="en">Popup Menu Button title</title>
                                    </meta>
                                </property>
                            </properties>
                        </type>
                    </types>
                </block>

                <property name="footer_copyright" type="text_line">
                    <meta>
                        <title lang="en">Footer Copyright Text</title>
                        <title lang="de">Footer Copyright Text</title>
                    </meta>
                </property>
            </properties>
        </section>

        <property name="custom_style" type="text_area">
            <meta>
                <title lang="en">Custom Style</title>
                <title lang="en">Custom Style</title>
            </meta>
        </property>
    </properties>
</template>

html

<ul class="list-inline quicklinks" property="footer_menu_block" typeof="collection">
    <li class="list-inline-item" rel="footer_menu_block" typeof="menu_item">
        <a href="#footerModal1" data-toggle="modal" property="menu_title">
            Imprints
        </a>
    </li>
    <li class="list-inline-item" rel="footer_menu_block" typeof="menu_item">
        <a href="#footerModal2" data-toggle="modal" property="menu_title">
            Impressum
        </a>
    </li>
</ul>

shouldn't that be property="name"? https://gist.github.com/apoorva-shah/c035c15ca13620e7a018082656684459#file-html-L3