diff --git a/app/controllers/code_ocean/files_controller.rb b/app/controllers/code_ocean/files_controller.rb
index a0dad3b1..a788e4df 100644
--- a/app/controllers/code_ocean/files_controller.rb
+++ b/app/controllers/code_ocean/files_controller.rb
@@ -27,8 +27,7 @@ module CodeOcean
           path = options[:path].try(:call) || @object
           respond_with_valid_object(format, notice: t('shared.object_created', model: @object.class.model_name.human), path: path, status: :created)
         else
-          # I have deleted ".file_extension" due to error "undefined method `file_extension' for nil:NilClass"
-          filename = (@object.path || '') + '/' + (@object.name || '') + (@object.file_type.file_extension || '')
+          filename = (@object.path || '') + '/' + (@object.name || '') + (@object.file_type.try(:file_extension) || '')
           format.html { redirect_to(options[:path]); flash[:danger] = t('files.error.filename', name: filename) }
           format.json { render(json: @object.errors, status: :unprocessable_entity) }
         end
diff --git a/spec/controllers/errors_controller_spec.rb b/spec/controllers/errors_controller_spec.rb
deleted file mode 100644
index f402e4c7..00000000
--- a/spec/controllers/errors_controller_spec.rb
+++ /dev/null
@@ -1,85 +0,0 @@
-require 'rails_helper'
-
-describe ErrorsController do
-  let(:error) { FactoryGirl.create(:error) }
-  let(:execution_environment) { error.execution_environment }
-  let(:user) { FactoryGirl.create(:admin) }
-  before(:each) { allow(controller).to receive(:current_user).and_return(user) }
-
-  describe 'POST #create' do
-    context 'with a valid error' do
-      let(:request) { proc { post :create, execution_environment_id: FactoryGirl.build(:error).execution_environment.id, error: FactoryGirl.attributes_for(:error), format: :json } }
-
-      context 'when a hint can be matched' do
-        let(:hint) { FactoryGirl.build(:ruby_syntax_error).message }
-
-        before(:each) do
-          expect_any_instance_of(Whistleblower).to receive(:generate_hint).and_return(hint)
-          request.call
-        end
-
-        expect_assigns(execution_environment: :execution_environment)
-
-        it 'does not create the error' do
-          allow_any_instance_of(Whistleblower).to receive(:generate_hint).and_return(hint)
-          expect { request.call }.not_to change(Error, :count)
-        end
-
-        it 'returns the hint' do
-          expect(response.body).to eq({hint: hint}.to_json)
-        end
-
-        expect_json
-        expect_status(200)
-      end
-
-      context 'when no hint can be matched' do
-        before(:each) do
-          expect_any_instance_of(Whistleblower).to receive(:generate_hint).and_return(nil)
-          request.call
-        end
-
-        expect_assigns(execution_environment: :execution_environment)
-
-        it 'creates the error' do
-          allow_any_instance_of(Whistleblower).to receive(:generate_hint)
-          expect { request.call }.to change(Error, :count).by(1)
-        end
-
-        expect_json
-        expect_status(201)
-      end
-    end
-
-    context 'with an invalid error' do
-      before(:each) { post :create, execution_environment_id: FactoryGirl.build(:error).execution_environment.id, error: {}, format: :json }
-
-      expect_assigns(error: Error)
-      expect_json
-      expect_status(422)
-    end
-  end
-
-  describe 'GET #index' do
-    before(:all) { FactoryGirl.create_pair(:error) }
-    before(:each) { get :index, execution_environment_id: execution_environment.id }
-
-    expect_assigns(execution_environment: :execution_environment)
-
-    it 'aggregates errors by message' do
-      expect(assigns(:errors).length).to eq(1)
-    end
-
-    expect_status(200)
-    expect_template(:index)
-  end
-
-  describe 'GET #show' do
-    before(:each) { get :show, execution_environment_id: execution_environment.id, id: error.id }
-
-    expect_assigns(error: :error)
-    expect_assigns(execution_environment: :execution_environment)
-    expect_status(200)
-    expect_template(:show)
-  end
-end
diff --git a/spec/models/submission_spec.rb b/spec/models/submission_spec.rb
index b97d5b88..3c297ca4 100644
--- a/spec/models/submission_spec.rb
+++ b/spec/models/submission_spec.rb
@@ -16,7 +16,7 @@ describe Submission do
     expect(described_class.create.errors[:user_type]).to be_present
   end
 
-  [:download, :render, :run, :test].each do |action|
+  [:render, :run, :test].each do |action|
     describe "##{action}_url" do
       let(:url) { submission.send(:"#{action}_url") }