diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 669c7518..91601b0b 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -14,9 +14,6 @@ class ApplicationController < ActionController::Base
     @current_user ||= ExternalUser.find_by(id: session[:external_user_id]) || login_from_session || login_from_other_sources
   end
 
-  def help
-  end
-
   def render_not_authorized
     redirect_to(:root, alert: t('application.not_authorized'))
   end
diff --git a/app/controllers/code_ocean/errors_controller.rb b/app/controllers/code_ocean/errors_controller.rb
new file mode 100644
index 00000000..6b594dae
--- /dev/null
+++ b/app/controllers/code_ocean/errors_controller.rb
@@ -0,0 +1,45 @@
+module CodeOcean
+  class ErrorsController < ApplicationController
+    before_action :set_execution_environment
+
+    def authorize!
+      authorize(@error || @errors)
+    end
+    private :authorize!
+
+    def create
+      @error = CodeOcean::Error.new(error_params)
+      authorize!
+      hint = Whistleblower.new(execution_environment: @error.execution_environment).generate_hint(@error.message)
+      respond_to do |format|
+        format.json do
+          if hint
+            render(json: {hint: hint})
+          else
+            head (@error.save ? :created : :unprocessable_entity)
+          end
+        end
+      end
+    end
+
+    def error_params
+      params[:error].permit(:message, :submission_id).merge(execution_environment_id: @execution_environment.id) if params[:error].present?
+    end
+    private :error_params
+
+    def index
+      @errors = CodeOcean::Error.for_execution_environment(@execution_environment).grouped_by_message.paginate(page: params[:page])
+      authorize!
+    end
+
+    def set_execution_environment
+      @execution_environment = ExecutionEnvironment.find(params[:execution_environment_id])
+    end
+    private :set_execution_environment
+
+    def show
+      @error = CodeOcean::Error.find(params[:id])
+      authorize!
+    end
+  end
+end
\ No newline at end of file
diff --git a/app/controllers/errors_controller.rb b/app/controllers/errors_controller.rb
deleted file mode 100644
index 6a843eeb..00000000
--- a/app/controllers/errors_controller.rb
+++ /dev/null
@@ -1,43 +0,0 @@
-class ErrorsController < ApplicationController
-  before_action :set_execution_environment
-
-  def authorize!
-    authorize(@error || @errors)
-  end
-  private :authorize!
-
-  def create
-    @error = Error.new(error_params)
-    authorize!
-    hint = Whistleblower.new(execution_environment: @error.execution_environment).generate_hint(@error.message)
-    respond_to do |format|
-      format.json do
-        if hint
-          render(json: {hint: hint})
-        else
-          head (@error.save ? :created : :unprocessable_entity)
-        end
-      end
-    end
-  end
-
-  def error_params
-    params[:error].permit(:message, :submission_id).merge(execution_environment_id: @execution_environment.id) if params[:error].present?
-  end
-  private :error_params
-
-  def index
-    @errors = Error.for_execution_environment(@execution_environment).grouped_by_message.paginate(page: params[:page])
-    authorize!
-  end
-
-  def set_execution_environment
-    @execution_environment = ExecutionEnvironment.find(params[:execution_environment_id])
-  end
-  private :set_execution_environment
-
-  def show
-    @error = Error.find(params[:id])
-    authorize!
-  end
-end
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 0e37dd07..8d16eb90 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -366,7 +366,7 @@ class SubmissionsController < ApplicationController
   end
 
   def store_error(stderr)
-    ::Error.create(submission_id: @submission.id, execution_environment_id: @submission.execution_environment.id, message: stderr)
+    CodeOcean::Error.create(submission_id: @submission.id, execution_environment_id: @submission.execution_environment.id, message: stderr)
   end
   private :store_error
 
diff --git a/app/models/code_ocean/error.rb b/app/models/code_ocean/error.rb
new file mode 100644
index 00000000..935962cf
--- /dev/null
+++ b/app/models/code_ocean/error.rb
@@ -0,0 +1,19 @@
+module CodeOcean
+  class Error < ApplicationRecord
+    belongs_to :execution_environment
+
+    scope :for_execution_environment, ->(execution_environment) { where(execution_environment_id: execution_environment.id) }
+    scope :grouped_by_message, -> { select('MAX(created_at) AS created_at, MAX(id) AS id, message, COUNT(id) AS count').group(:message).order('count DESC') }
+
+    validates :execution_environment_id, presence: true
+    validates :message, presence: true
+
+    def self.nested_resource?
+      true
+    end
+
+    def to_s
+      id.to_s
+    end
+  end
+end
diff --git a/app/models/error.rb b/app/models/error.rb
deleted file mode 100644
index 623e3558..00000000
--- a/app/models/error.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-class Error < ApplicationRecord
-  belongs_to :execution_environment
-
-  scope :for_execution_environment, ->(execution_environment) { where(execution_environment_id: execution_environment.id) }
-  scope :grouped_by_message, -> { select('MAX(created_at) AS created_at, MAX(id) AS id, message, COUNT(id) AS count').group(:message).order('count DESC') }
-
-  validates :execution_environment_id, presence: true
-  validates :message, presence: true
-
-  def self.nested_resource?
-    true
-  end
-end
diff --git a/app/policies/code_ocean/error_policy.rb b/app/policies/code_ocean/error_policy.rb
new file mode 100644
index 00000000..376af8d8
--- /dev/null
+++ b/app/policies/code_ocean/error_policy.rb
@@ -0,0 +1,7 @@
+module CodeOcean
+  class ErrorPolicy < AdminOrAuthorPolicy
+    def author?
+      @user == @record.execution_environment.author
+    end
+  end
+end
diff --git a/app/policies/error_policy.rb b/app/policies/error_policy.rb
deleted file mode 100644
index 632f8b20..00000000
--- a/app/policies/error_policy.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-class ErrorPolicy < AdminOrAuthorPolicy
-  def author?
-    @user == @record.execution_environment.author
-  end
-end
diff --git a/app/views/application/_breadcrumbs.html.slim b/app/views/application/_breadcrumbs.html.slim
index 216dcc7f..151e33e8 100644
--- a/app/views/application/_breadcrumbs.html.slim
+++ b/app/views/application/_breadcrumbs.html.slim
@@ -1,6 +1,6 @@
 - if current_user.try(:internal_user?)
   ul.breadcrumb
-    - if model = Kernel.const_get(controller_name.classify) rescue nil
+    - if model = Kernel.const_get(controller_path.classify) rescue nil
       - object = model.find_by(id: params[:id])
       - if model.try(:nested_resource?)
         li = model.model_name.human(count: 2)
diff --git a/app/views/application/_navigation.html.slim b/app/views/application/_navigation.html.slim
index 82c6271b..168a747f 100644
--- a/app/views/application/_navigation.html.slim
+++ b/app/views/application/_navigation.html.slim
@@ -10,7 +10,7 @@
           li = link_to(t('breadcrumbs.statistics.show'), statistics_path)
           li.divider
         = render('navigation_submenu', title: t('activerecord.models.exercise.other'),
-                models: [Exercise, ExerciseCollection, ProxyExercise, Tag], link: exercises_path, cached: true)
+                models: [Exercise, ExerciseCollection, ProxyExercise, Tag, Submission], link: exercises_path, cached: true)
         = render('navigation_submenu', title: t('navigation.sections.users'), models: [InternalUser, ExternalUser],
                 cached: true)
         = render('navigation_collection_link', model: ExecutionEnvironment, cached: true)
diff --git a/app/views/errors/index.html.slim b/app/views/code_ocean/errors/index.html.slim
similarity index 85%
rename from app/views/errors/index.html.slim
rename to app/views/code_ocean/errors/index.html.slim
index 2db0d9de..dbfa2312 100644
--- a/app/views/errors/index.html.slim
+++ b/app/views/code_ocean/errors/index.html.slim
@@ -1,10 +1,10 @@
-h1 = ::Error.model_name.human(count: 2)
+h1 = CodeOcean::Error.model_name.human(count: 2)
 
 .table-responsive
   table.table
     thead
       tr
-        th = t('.count')
+        th = t('errors.index.count')
         th = t('activerecord.attributes.error.message')
         th = t('shared.created_at')
         th = t('shared.actions')
diff --git a/app/views/errors/show.html.slim b/app/views/code_ocean/errors/show.html.slim
similarity index 77%
rename from app/views/errors/show.html.slim
rename to app/views/code_ocean/errors/show.html.slim
index f5bf9a08..1bb6623e 100644
--- a/app/views/errors/show.html.slim
+++ b/app/views/code_ocean/errors/show.html.slim
@@ -1,4 +1,4 @@
-h1 = ::Error.model_name.human
+h1 = CodeOcean::Error.model_name.human
 
 = row(label: 'error.message', value: @error.message)
 = row(label: 'shared.created_at', value: l(@error.created_at, format: :short))
diff --git a/app/views/shared/_edit_button.html.slim b/app/views/shared/_edit_button.html.slim
index 1fc1870e..7ccd60f1 100644
--- a/app/views/shared/_edit_button.html.slim
+++ b/app/views/shared/_edit_button.html.slim
@@ -1 +1,3 @@
-= link_to(t('shared.edit'), local_assigns.fetch(:path, send(:"edit_#{object.class.name.underscore}_path", object)), class: 'btn btn-default pull-right')
+// default value for fetch will always be evaluated even if it is not returned
+- link_target = local_assigns.fetch(:path, false) || send(:"edit_#{object.class.name.underscore}_path", object)
+= link_to(t('shared.edit'), link_target, class: 'btn btn-default pull-right')
diff --git a/app/views/shared/_new_button.html.slim b/app/views/shared/_new_button.html.slim
index 3ed54d2b..9037487b 100644
--- a/app/views/shared/_new_button.html.slim
+++ b/app/views/shared/_new_button.html.slim
@@ -1,4 +1,6 @@
 - if policy(model).new?
-  a.btn.btn-success href=local_assigns.fetch(:path, send(:"new_#{model.model_name.singular}_path"))
+  // default value for fetch will always be evaluated even if it is not returned
+  - href_target = local_assigns.fetch(:path, false) || send(:"new_#{model.model_name.singular}_path")
+  a.btn.btn-success href=href_target
     i.fa.fa-plus
     = t('shared.new_model', model: model.model_name.human)
diff --git a/config/routes.rb b/config/routes.rb
index 7c1f317b..b65d401e 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -28,7 +28,7 @@ Rails.application.routes.draw do
   delete '/comment_by_id', to: 'comments#destroy_by_id'
   put '/comments', to: 'comments#update'
 
-  resources :subscriptions do
+  resources :subscriptions, only: [:create, :destroy] do
     member do
       get :unsubscribe, to: 'subscriptions#destroy'
     end
@@ -40,8 +40,6 @@ Rails.application.routes.draw do
     get 'dashboard', to: 'dashboard#show'
   end
 
-  get '/help', to: 'application#help'
-
   get 'statistics/', to: 'statistics#show'
   get 'statistics/graphs', to: 'statistics#graphs'
   get 'statistics/graphs/user-activity', to: 'statistics#user_activity'
@@ -65,7 +63,7 @@ Rails.application.routes.draw do
       get :statistics
     end
 
-    resources :errors, only: [:create, :index, :show]
+    resources :errors, only: [:create, :index, :show], controller: 'code_ocean/errors'
     resources :hints
   end
 
diff --git a/db/seeds/development.rb b/db/seeds/development.rb
index 0aedc789..fab9a989 100644
--- a/db/seeds/development.rb
+++ b/db/seeds/development.rb
@@ -11,7 +11,7 @@ Rails.application.routes.default_url_options = Rails.application.config.action_m
 ExecutionEnvironment.create_factories
 
 # errors
-Error.create_factories
+CodeOcean::Error.create_factories
 
 # exercises
 @exercises = find_factories_by_class(Exercise).map(&:name).map { |factory_name| [factory_name, FactoryBot.create(factory_name)] }.to_h
diff --git a/spec/factories/error.rb b/spec/factories/error.rb
index 427fee7d..0bcae320 100644
--- a/spec/factories/error.rb
+++ b/spec/factories/error.rb
@@ -1,5 +1,5 @@
 FactoryBot.define do
-  factory :error, class: Error do
+  factory :error, class: CodeOcean::Error do
     association :execution_environment, factory: :ruby
     message { "exercise.rb:4:in `<main>': undefined local variable or method `foo' for main:Object (NameError)" }
   end
diff --git a/spec/models/error_spec.rb b/spec/models/error_spec.rb
index 7f9f405a..aa111b3c 100644
--- a/spec/models/error_spec.rb
+++ b/spec/models/error_spec.rb
@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-describe Error do
+describe CodeOcean::Error do
   let(:error) { described_class.create }
 
   it 'validates the presence of an execution environment' do