diff --git a/app/assets/javascripts/editor/participantsupport.js.erb b/app/assets/javascripts/editor/participantsupport.js.erb
index 5ea4cc9e..91e9f0d1 100644
--- a/app/assets/javascripts/editor/participantsupport.js.erb
+++ b/app/assets/javascripts/editor/participantsupport.js.erb
@@ -59,6 +59,8 @@ CodeOceanEditorCodePilot = {
   }
 };
 
+//Request for comments does currently not work on staging platform (no relative root_url used here).
+//To fix this rely on ruby routes
 CodeOceanEditorRequestForComments = {
   requestComments: function () {
     var user_id = $('#editor').data('user-id');
diff --git a/spec/controllers/exercises_controller_spec.rb b/spec/controllers/exercises_controller_spec.rb
index 278f9967..43dada43 100644
--- a/spec/controllers/exercises_controller_spec.rb
+++ b/spec/controllers/exercises_controller_spec.rb
@@ -231,7 +231,7 @@ describe ExercisesController do
     let(:output) { {} }
     let(:request) { post :submit, format: :json, id: exercise.id, submission: {cause: 'submit', exercise_id: exercise.id} }
     let!(:external_user) { FactoryGirl.create(:external_user) }
-    let!(:lti_parameter) { FactoryGirl.create(:lti_parameter) }
+    let!(:lti_parameter) { FactoryGirl.create(:lti_parameter, external_user: external_user, exercise: exercise) }
 
     before(:each) do
       allow_any_instance_of(Submission).to receive(:normalized_score).and_return(1)