I insert language switcher in my page_header.html.twig as described in the documentation https://doc.ez.no/display/EZP/Language+Switcher
and defined my pagelayout.html.twig to display legacy modules (content/search for example).
But it raise an error when displaying the page content/search :
An exception has been thrown during the rendering of a template ("When generating an eZ Publish legacy fallback route, "uri" parameter must be provided.") in EzConsultingBundle:Language:switcher.html.twig at line 17.
And this is my template twig :
It seems that in the variable routeRef sent to the template, "route" is set to "ez_legacy" and there is not any "params.parameters".