diff --git a/app/controllers/code_ocean/files_controller.rb b/app/controllers/code_ocean/files_controller.rb
index 66733b45..08ca897d 100644
--- a/app/controllers/code_ocean/files_controller.rb
+++ b/app/controllers/code_ocean/files_controller.rb
@@ -22,7 +22,7 @@ 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"
+          # 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 || '')
           format.html { redirect_to(options[:path]); flash[:danger] = t('files.error.filename', name: filename) }
           format.json { render(json: @object.errors, status: :unprocessable_entity) }
diff --git a/app/controllers/errors_controller.rb b/app/controllers/errors_controller.rb
index bf327f64..667b186d 100644
--- a/app/controllers/errors_controller.rb
+++ b/app/controllers/errors_controller.rb
@@ -8,7 +8,7 @@ class ErrorsController < ApplicationController
 
   def create
     @error = Error.new(error_params)
-    authorize @error
+    authorize!
     hint = Whistleblower.new(execution_environment: @error.execution_environment).generate_hint(@error.message)
     respond_to do |format|
       format.json do
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 1fec0b1b..a6354d8d 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -246,7 +246,8 @@ class SubmissionsController < ApplicationController
   end
 
   def stop
-    Rails.logger.debug('stopping submission ' + @submission)
+    # temporary disabled
+    # Rails.logger.error('stopping submission ' + @submission)
     container = Docker::Container.get(params[:container_id])
     DockerClient.destroy_container(container)
   rescue Docker::Error::NotFoundError
diff --git a/spec/controllers/submissions_controller_spec.rb b/spec/controllers/submissions_controller_spec.rb
index 209ba384..8d83943c 100644
--- a/spec/controllers/submissions_controller_spec.rb
+++ b/spec/controllers/submissions_controller_spec.rb
@@ -200,6 +200,8 @@ describe SubmissionsController do
 
     context 'when the container can be found' do
       before(:each) do
+        #not sure where is a correct place for this call. Need to change structure of this test?
+        #expect(Rails.logger).to receive(:error).with(/error message/)
         expect(Docker::Container).to receive(:get).and_return(CONTAINER)
         request.call
       end
@@ -213,6 +215,7 @@ describe SubmissionsController do
 
     context 'when the container cannot be found' do
       before(:each) do
+        #expect(Rails.logger).to receive(:error).with(/error message/)
         expect(Docker::Container).to receive(:get).and_raise(Docker::Error::NotFoundError)
         request.call
       end