diff --git a/app/models/course.rb b/app/models/course.rb
index ceced2301..b828af0ce 100644
--- a/app/models/course.rb
+++ b/app/models/course.rb
@@ -34,7 +34,7 @@ class Course < ActiveRecord::Base
                      :delete_permission => :manage_files
 
   validates_presence_of :password, :term
-  validates_format_of  :class_period, :message => "class period can only digital!", :with =>/^[1-9]\d*$/
+  validates_format_of  :class_period, :message => l(:error_class_period_only_num), :with =>/^[1-9]\d*$/
 
   after_save :create_board_sync
   before_destroy :delete_all_members
diff --git a/app/views/layouts/base_courses.html.erb b/app/views/layouts/base_courses.html.erb
index 2601d7c7e..ac5cc104d 100644
--- a/app/views/layouts/base_courses.html.erb
+++ b/app/views/layouts/base_courses.html.erb
@@ -66,7 +66,6 @@
               <tr>
                 <!-- modified by zjc 课程名称添加超链接 -->
                 <td class="info-course"><%= link_to @course.name,course_path(@course) %></td>
-                <td class="info-course"><%= @course.name %></td>
               </tr>
               <tr>
                 <td align="center">
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 4e2ba0781..4c177b58e 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -186,6 +186,7 @@ en:
   notice_account_deleted: "Your account has been permanently deleted."
   notice_user_successful_create: "User %{id} created."
 
+  error_class_period_only_num: "class period can only digital"
   error_can_t_load_default_data: "Default configuration could not be loaded: %{value}"
   error_scm_not_found: "The entry or revision was not found in the repository."
   error_scm_command_failed: "An error occurred when trying to access the repository: %{value}"
diff --git a/config/locales/zh.yml b/config/locales/zh.yml
index cd3e83b38..71972a6fd 100644
--- a/config/locales/zh.yml
+++ b/config/locales/zh.yml
@@ -196,6 +196,7 @@ zh:
   
   error_complete_occupation: "请您填写工作单位，否则本系统的部分功能将无法正常使用。"
 
+  error_class_period_only_num: "课程学时只能为数字"
   error_can_t_load_default_data: "无法载入默认设置：%{value}"
   error_scm_not_found: "版本库中不存在该条目和（或）其修订版本。"
   error_scm_command_failed: "访问版本库时发生错误：%{value}"
diff --git a/db/migrate/20140618105213_migrate_course_students.rb b/db/migrate/20140618105213_migrate_course_students.rb
index b9ac66714..ef037682a 100644
--- a/db/migrate/20140618105213_migrate_course_students.rb
+++ b/db/migrate/20140618105213_migrate_course_students.rb
@@ -3,7 +3,7 @@ class MigrateCourseStudents < ActiveRecord::Migration
     # 原课程的学生数据迁移成新模式
     StudentsForCourse.all.each do |student|
         project = Project.find_by_id(student.course_id)
-        if project
+        if project && project.course_extra
           student.course_id = project.course_extra.id
           student.save
         end
diff --git a/lib/redmine/activity/fetcher.rb b/lib/redmine/activity/fetcher.rb
index 6a1b88b59..b95ae2bc3 100644
--- a/lib/redmine/activity/fetcher.rb
+++ b/lib/redmine/activity/fetcher.rb
@@ -102,16 +102,18 @@ module Redmine
         @options[:limit] = options[:limit]
         @scope.each do |event_type|
           constantized_providers(event_type).each do |provider|
-			 if event_type.to_s != 'course_journals_for_messages'
-            	cur_objs = provider.find_events1(event_type, @user, from, to, @options)
- 			end
-            cur_objs.each do |cur_obj|
-              if cur_obj.class == Issue
-                if cur_obj.project != nil && cur_obj.project.project_status != nil
+            if event_type.to_s != 'course_journals_for_messages'
+              cur_objs = provider.find_events1(event_type, @user, from, to, @options)
+            end
+            if cur_objs
+              cur_objs.each do |cur_obj|
+                if cur_obj.class == Issue
+                  if cur_obj.project != nil && cur_obj.project.project_status != nil
+                    e += [cur_obj]
+                  end
+                else
                   e += [cur_obj]
                 end
-              else
-                e += [cur_obj]
               end
             end
           end