Problem with the configuration of my toolbar

Excuse my English, I don’t speak it very well.

I am starting to use django cms, in my project I am trying to access the menus of my toolbar with the following code

@toolbar_pool.register
class MyBarToolbar(CMSToolbar):
    def populate(self):
        list_menu=self.toolbar.find_items(Menu)

and I get the following error:

Internal Server Error: /es/
Traceback (most recent call last):
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\core\handlers\base.py", line 204, in _get_response
    response = response.render()
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\response.py", line 105, in render
    self.content = self.rendered_content
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\response.py", line 83, in rendered_content
    return template.render(context, self._request)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\backends\django.py", line 61, in render
    return self.template.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 170, in render
    return self._render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 162, in _render
    return self.nodelist.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 938, in render
    bit = node.render_annotated(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 905, in render_annotated
    return self.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 162, in _render
    return self.nodelist.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 938, in render
    bit = node.render_annotated(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 905, in render_annotated
    return self.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\classytags\core.py", line 151, in render
    return self.render_tag(context, **kwargs)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\sekizai\templatetags\sekizai_tags.py", line 87, in render_tag
    rendered_contents = nodelist.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 938, in render
    bit = node.render_annotated(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\django\template\base.py", line 905, in render_annotated
    return self.render(context)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\classytags\core.py", line 151, in render
    return self.render_tag(context, **kwargs)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\templatetags\cms_tags.py", line 443, in render_tag
    return toolbar.render_with_structure(context, nodelist)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\toolbar\toolbar.py", line 467, in render_with_structure
    self.populate()
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\toolbar\toolbar.py", line 407, in populate
    self._call_toolbar('populate')
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\toolbar\toolbar.py", line 434, in _call_toolbar
    getattr(toolbar, func_name)()
  File "C:\Django CMS\Proyecto django cms-blog\Proyecto\ProbandoBlog\cms_toolbars.py", line 11, in populate
    list_menu=self.toolbar.find_items(Menu)
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\toolbar\items.py", line 88, in find_items
    results.append(ItemSearchResult(candidate, self._item_position(candidate)))
  File "C:\Django CMS\Proyecto django cms-blog\EntornoVirtual\lib\site-packages\cms\toolbar\toolbar.py", line 375, in _item_position
    return self.left_items.index(item)
ValueError: <Menu:Idioma> is not in list        

I guess it has to do with the language setting, but I have no idea how to fix it.

I would appreciate any help you could give me.

Thanks