HTML Sitemap (CMS page) is blank

[webmasterpcx]

Hi !

I have an issue with my sitemap page... On front office this page is blank and I do not know how to fix it.

I enabled debug mode, you can see full error report on picture attachment. I see that there is an error notice : "Notice: Undefined index: sitemap"

Here is the file sitemap.tpl located in /template/cms of my theme :

{extends file='page.tpl'}

{block name='page_title'}
  {l s='Sitemap' d='Shop.Theme.Global'}
{/block}

{block name='page_content_container'}
  <div id="sitemap-tree" class="sitemap">
    <div class="tree-top">
      <a href="{$urls.base_url}" title="{$shop.name}"></a>
    </div>
    <ul class="tree">
      {foreach $sitemap as $item}
        {if isset($item.children)}
          {foreach $item.children as $child}
            {include file='cms/_partials/sitemap-tree-branch.tpl' node=$child}
          {/foreach}
        {/if}
      {/foreach}
    </ul>
  </div>
{/block}

An here is file sitemap-tree-branch.tpl located in /template/cms/partials of my theme :

<li>
  <a id="{$node.id}" href="{$node.url}" title="{$node.label}">{$node.label}</a>
  {if isset($node.children) && $node.children|@count > 0}
    <ul>
      {foreach $node.children as $child}
        {include file='cms/_partials/sitemap-tree-branch.tpl' node=$child}
      {/foreach}
    </ul>
  {/if}
</li>

I really don't know what to do to fix this and I need to have an HTML sitemap on my website...

Thank you !

Best regards,