macro cause "This site can’t be reached"

{%- macro leaf_item(leaf, url) %}
    <li id="category_{{ leaf.getId() }}">
        <div class="item">
            <span class="title">{{ leaf.getTitle() }}</span>
            <span class="info">({{ leaf.getSlug() }})</span>
            <a href="{{ url }}category/admin/edit/{{ leaf.getId() }}"><i class="icon edit"></i></a>
            <a href="javascript:void(0);" onclick="deleteCategory({{ leaf.getId() }}, this)" class="delete"><i class="icon trash"></i></a>
        </div>
        {% if leaf.hasChildren() %}
            <ol>
                {% for child in leaf.children() %}
                    {{ leaf_item(child, url) }}
                {% endfor %}
            </ol>
        {% endif %}
    </li>
{%- endmacro %}

<div class="ui blue segment">
    You can drag and drop tree elements to change order and relations
</div>

{% for root, root_title in roots %}
    <div class="ui blue segment">
        <h3>{{ root_title }}</h3>

        <ol class="sortable" id="root_{{ root }}">

            {% set tree = category_helper.treeUpperLeafs(root) %}
            {% for leaf in tree %}
                {{ leaf_item(leaf, url.get()) }}
            {% endfor %}

        </ol>

        <a class="save ui button primary" id="save-root-{{ root }}" data-root="{{ root }}">
            <i class="save icon"></i> Save
        </a>
        <a href="javascript:void(0);" data-root="{{ root }}" class="add ui button positive">
            <i class="icon plus"></i> Add
        </a>
    </div>
{% endfor %}

I use macro volt template, but I can't open the page from yesterday. On my brower it's showing :

This site can’t be reached

The connection was reset. Try: Reloading the page Checking the connection Checking the proxy and the firewall ERR_CONNECTION_RESET

....

If I delete endmacro block on view template, the page is available.

So, May I know what happend ? how to fix it ?