Fix bug.

app/controllers/application_forms_controller.rb

@@ -805,6 +805,5 @@ class ApplicationFormsController < ApplicationController
       template_data:{'application_form_id'=>application_form_id,'locale'=>I18n.locale,'extra_text'=> extra_text}.merge(extra_data),
       mail_lang: I18n.locale)
     end
-    mail.save  
   end
 end

app/models/application_form_signup.rb

@@ -65,10 +65,9 @@ class ApplicationFormSignup
       self.process_stage = enable_idx.nil? ? 0 : (enable_idx + 1)
     end
     if self.serial_number.nil?
-      s = ApplicationFormSetting.first
-      s.last_serial_number += 1
-      self.serial_number = s.last_serial_number
-    	s.save(:validate=>false)
+      last_serial_number = ApplicationFormSetting.max(:last_serial_number).to_i
+      self.serial_number = last_serial_number + 1
+      ApplicationFormSetting.update_all({"$inc"=>{"last_serial_number"=>1}})
     end
   end
   after_destroy do

config/routes.rb

@@ -2,6 +2,7 @@ Rails.application.routes.draw do
 
   locales = Site.first.in_use_locales rescue I18n.available_locales
   Thread.new do
+    ApplicationFormEmailSet.where(:field_name=>nil).destroy
   end
   scope "(:locale)", locale: Regexp.new(locales.join("|")) do
    namespace :admin do