Missing partial error but lookup_context find it.

Hi everyone,
I'm get missing partial error even lookup_context find it.

my partial is in view/unicorns and partials name is _unicorn_card.html.erb

here is my controller code:

respond_to do |format|
      format.html
      format.text { render partial: 'unicorns/unicorn_card', locals: {unicorns: @unicorns}, format: [:html] rescue redirect_to unicorns_path}
    end

It must be a pretty dumb but i don't find it, any clue ?