diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 01bb48bcc1f..3e6a3731e7c 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -54,6 +54,8 @@ def new
   end
 
   def create
+    logger.info "[Signup] 1. start create. #{user_params[:email]}"
+
     @user = User.new(user_params)
     @user.course_id ||= Course.first.id
     @user.free = true if @user.trainee?
@@ -80,11 +82,14 @@ def target_allowlist
   end
 
   def create_free_user!
+    logger.info "[Signup] 2. start create free user. #{@user.email}"
     if @user.save
+      logger.info "[Signup] 3. after save free user. #{@user.email}"
       UserMailer.welcome(@user).deliver_now
       notify_to_mentors(@user)
       notify_to_chat(@user)
       Newspaper.publish(:student_or_trainee_create, @user) if @user.trainee?
+      logger.info "[Signup] 4. after create times channel for free user. #{@user.email}"
       redirect_to root_url, notice: 'サインアップメールをお送りしました。メールからサインアップを完了させてください。'
     else
       render 'new'
@@ -93,6 +98,7 @@ def create_free_user!
 
   # rubocop:disable Metrics/MethodLength, Metrics/BlockLength
   def create_user!
+    logger.info "[Signup] 2. start create user. #{@user.email}"
     @user.with_lock do
       unless @user.validate
         render 'new'
@@ -108,6 +114,7 @@ def create_user!
 
       token = params[:idempotency_token]
 
+      logger.info "[Signup] 3. before create subscription. #{@user.email}"
       begin
         customer = Card.new.create(@user, params[:stripeToken], token)
         subscription = Subscription.new.create(customer['id'], "#{token}-subscription")
@@ -117,15 +124,18 @@ def create_user!
         render 'new'
         return false
       end
+      logger.info "[Signup] 4. after create subscription.#{@user.email}"
 
       @user.customer_id = customer['id']
       @user.subscription_id = subscription['id']
 
       if @user.save
+        logger.info "[Signup] 5. after save user. #{@user.email}"
         UserMailer.welcome(@user).deliver_now
         notify_to_mentors(@user)
         notify_to_chat(@user)
         Newspaper.publish(:student_or_trainee_create, @user) if @user.student?
+        logger.info "[Signup] 8. after create times channel. #{@user.email}"
         redirect_to root_url, notice: 'サインアップメールをお送りしました。メールからサインアップを完了させてください。'
       else
         render 'new'
diff --git a/app/models/discord/server.rb b/app/models/discord/server.rb
index 0627d68b89e..d3f784e16a2 100644
--- a/app/models/discord/server.rb
+++ b/app/models/discord/server.rb
@@ -8,7 +8,10 @@ class Server
     class << self
       def create_text_channel(name:, parent: nil)
         guild = Discord::Server.find_by(id: guild_id, token: authorize_token)
-        return nil if guild.blank?
+        if guild.blank?
+          Rails.logger.error "[Discord API] Do not find server. guild_id: #{guild_id}, token: #{authorize_token}"
+          return nil
+        end
 
         channel_type = Discordrb::Channel::TYPES[:text]
         guild.create_channel(name, channel_type, parent: parent)
diff --git a/app/models/discord/times_channel.rb b/app/models/discord/times_channel.rb
index 2fb6f78bf07..c5666f099b6 100644
--- a/app/models/discord/times_channel.rb
+++ b/app/models/discord/times_channel.rb
@@ -8,6 +8,8 @@ def to_channel_name(username)
       end
     end
 
+    attr_reader :name
+
     def initialize(username)
       @name = Discord::TimesChannel.to_channel_name(username)
     end
diff --git a/test/models/discord/server_test.rb b/test/models/discord/server_test.rb
index 87ff1763e5b..5c43da5859e 100644
--- a/test/models/discord/server_test.rb
+++ b/test/models/discord/server_test.rb
@@ -91,7 +91,7 @@ class ServerTest < ActiveSupport::TestCase
           Discord::Server.authorize_token = 'Bot invalid token'
           actual = Discord::Server.create_text_channel(name: 'wakaran🔰')
           assert_nil actual
-          assert_equal '[Discord API] 401: Unauthorized', logs.pop
+          assert_equal '[Discord API] Do not find server. guild_id: 1234567890123456789, token: Bot invalid token', logs.pop
         end
       end
     end
diff --git a/test/models/times_channel_destroyer_test.rb b/test/models/times_channel_destroyer_test.rb
index edda241daa7..91d736156a7 100644
--- a/test/models/times_channel_destroyer_test.rb
+++ b/test/models/times_channel_destroyer_test.rb
@@ -2,7 +2,7 @@
 
 require 'test_helper'
 
-class TimesChannelCreatorTest < ActiveSupport::TestCase
+class TimesChannelDestroyerTest < ActiveSupport::TestCase
   test '#call' do
     logs = []
     user = users(:hajime)