Missing partial session/_login_form

Started GET "/session/login_form" for 127.0.0.1 at 2017-08-14 08:19:40 +0000
Processing by SessionController#login_form as JS
Completed 500 Internal Server Error in 28ms (ActiveRecord: 0.0ms)

ActionView::MissingTemplate (Missing partial session/_login_form with {:locale=>[:nl, :en], :formats=>[:js, :html, :xml, :html, :text, :js, :css, :ics, :csv, :vcf, :png, :jpeg, :gif, :bmp, :tiff, :mpeg, :xml, :rss, :atom, :yaml, :multipart_form, :url_encoded_form, :json, :pdf, :zip], :variants=>[], :handlers=>[:erb, :builder, :raw, :ruby, :haml, :rjs]}. Searched in:
  * "/srv/crabgrass/app/views"
  * "/srv/crabgrass/extensions/pages/discussion_page/app/views"
  * "/srv/crabgrass/extensions/pages/asset_page/app/views"
  * "/srv/crabgrass/extensions/pages/survey_page/app/views"
  * "/srv/crabgrass/extensions/pages/rate_many_page/app/views"
  * "/srv/crabgrass/extensions/pages/gallery_page/app/views"
  * "/srv/crabgrass/extensions/pages/wiki_page/app/views"
  * "/srv/crabgrass/extensions/pages/task_list_page/app/views"
  * "/srv/crabgrass/extensions/pages/ranked_vote_page/app/views"
  * "/srv/crabgrass/extensions/pages/event_page/app/views"
):
  app/controllers/common/application/before_filters.rb:19:in `render_with_view_setup'
  app/controllers/session_controller.rb:41:in `login_form'