Twig form (from symfony) variable not found -

I'm trying to get a widget of child elements (radio buttons in this case) as a I am coming. Read variables for trouble loop, but I have no problem to him just before reading it

Thanks in advance

  {% form_theme agregarAnio _self%} of & lt ; Div id = "agregarAnioDLG" title = "Agrregr Aeno" & gt; {{Form_start (Agregranio)}} {{Form_arrors (Agregranio)}} {{Form_lebl (Agregraniokaniodetalale)}} {{Form_arrors (Agregraniokaniodetalale)}} {{Form_vijet (Agregraniokaniodetalale)}} & lt; Div class = 'form group' & gt; {% Block choice_widget_expanded%} & lt; div {{Block ( 'widget_container_attributes')}} class = 'call SM-9' & gt; {For child AgregarAnio.anioHabilitado%%} {# line 121 #} {{form_widget (child, { 'attr': { 'name': 'inlineRadioOptions', 'id': 'inlineRadio' ~ loop.index}} }}} {{Form_label (child)}} {% endfor%} & lt; / Div & gt; <%> Endblock option_widget_expanded%}  

block

  {% Block option_widget_expanded%}  

The theme is overwritten, this is not within the render of your form. It should be normal I suggest you remove it, and its endblock