Error: Method “currentAncestor” for object “Knp\Menu\MenuItem” does not exist in Sonata

0_current_ancestor_error.twig

{# app/resources/SonataBlockBundle/views/Block/ block_side_menu_template.html.twig #}

{# Fixed changing this : #}

{%- if item.current %}
{%- set classes = classes|merge([options.currentClass]) %}
{%- elseif item.currentAncestor %}
{%- set classes = classes|merge([options.ancestorClass]) %}
{%- endif %}

{# For this : #}

{%- if matcher.isCurrent(item) %}
{%- set classes = classes|merge([options.currentClass]) %}
{%- elseif matcher.isAncestor(item, options.depth) %} 
{%- set classes = classes|merge([options.ancestorClass]) %}
{%- endif %}

1_current_ancestor_error.md

At:

/var/www/html/MySymProject/vendor/sonata-project/block-bundle/Resources/views/Block/block_side_menu_template.html.twig

But remember to do it extending the template in app/resources/SonataBlockBundle/views/Block/ block_side_menu_template.html.twig

Already done in Gpstracker project, is just a matter of copy and paste the file