调整

app/helpers/application_helper.rb

@@ -6490,7 +6490,7 @@ def visable_attachemnts_incourse course
         member = course.members.where(:user_id => User.current.id).first
         if member.try(:course_group_id).to_i == 0 && attachment.unified_setting
           result << attachment
-        elsif attachment.attachment_group_settings.where("course_group_id = #{member.try(:course_group_id)} and publish_time > '#{Time.now}'").count == 0
+        elsif attachment.attachment_group_settings.where("course_group_id = #{member.try(:course_group_id).to_i} and publish_time > '#{Time.now}'").count == 0
           result << attachment
         end
       end