diff --git a/app/controllers/concerns/lti.rb b/app/controllers/concerns/lti.rb
index 9d229013..47bffb6f 100644
--- a/app/controllers/concerns/lti.rb
+++ b/app/controllers/concerns/lti.rb
@@ -163,7 +163,7 @@ module Lti
   private :send_scores
 
   def send_score_for(submission, user, score)
-    return {status: 'error', user:} unless user.external_user? && user.consumer
+    return {status: 'unsupported', user:} unless user.external_user? && user.consumer
 
     lti_parameter = user.lti_parameters.find_by(exercise: submission.exercise, study_group: submission.study_group)
     provider = build_tool_provider(consumer: user.consumer, parameters: lti_parameter&.lti_parameters)
diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index a1def858..7d9e104b 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -50,8 +50,10 @@ class SessionsController < ApplicationController
   def destroy_through_lti
     @submission = Submission.find(params[:submission_id])
     authorize(@submission, :show?)
-    lti_parameter = current_user.lti_parameters.find_by(exercise: @submission.exercise, study_group_id: current_user.current_study_group_id)
-    @url = consumer_return_url(build_tool_provider(consumer: current_user.consumer, parameters: lti_parameter&.lti_parameters))
+    if current_user.external_user?
+      @lti_parameter = current_user.lti_parameters.find_by(exercise: @submission.exercise, study_group_id: current_user.current_study_group_id)
+      @url = consumer_return_url(build_tool_provider(consumer: current_user.consumer, parameters: @lti_parameter&.lti_parameters))
+    end
   end
 
   def destroy
diff --git a/app/views/sessions/destroy_through_lti.html.slim b/app/views/sessions/destroy_through_lti.html.slim
index 2a44b4e9..8399d9bf 100644
--- a/app/views/sessions/destroy_through_lti.html.slim
+++ b/app/views/sessions/destroy_through_lti.html.slim
@@ -1,10 +1,8 @@
 h1 = t('.headline')
 
-- consumer = current_user.consumer
-
 p
-  = t(".success_#{consumer ? 'with' : 'without'}_outcome", consumer: consumer)
-  ==< t(".finished_#{consumer ? 'with' : 'without'}_consumer", consumer: h(consumer.name), url: @url)
+  = t(".success_#{@lti_parameter ? 'with' : 'without'}_outcome", consumer: current_user.consumer)
+  ==< t(".finished_#{@lti_parameter ? 'with' : 'without'}_consumer", consumer: h(current_user.consumer.name), url: @url)
   =< t(".do_not_use_backbutton")
 
 h2 = t('shared.statistics')