Rails 6 passanger error log - expected file to define constant

I got this error in passanger error log:

expected file /var/www/my_app/app/controllers/categoriesnames.rb to define constant 
Categoriesnames, but didn't (Zeitwerk::NameError)

categoriesnames.rb

class CategoriesNamesController < ApplicationController
before_action :authenticate_user!



# Only allow a list of trusted parameters through.
def categoriesnames_params
    params.require(:categoriesname).permit(

                                    :categories_name,
                                    :strona_id,
                                    :category_id
                                    
                                   )
    end


end

PS. it works on localhost