#371

backend/app/controllers/gekanator_games_controller.rb

@@ -192,7 +192,10 @@ class GekanatorGamesController < ApplicationController
       answer_value = answer['answer'].to_s
       next if answer_value.blank? || answer_value == 'unknown'
 
-      question = accepted_questions[answer['question_id'].to_s]
+      question_id = game_answer_question_id(answer)
+      next if question_id.blank?
+
+      question = accepted_questions[question_id.to_s]
       next unless learnable_game_answer_question?(question)
 
       example =
@@ -251,6 +254,7 @@ class GekanatorGamesController < ApplicationController
   end
 
   def learnable_game_answer_question? question
+    return false if question.nil?
     return true if question.kind == 'post_similarity'
     return false unless question.kind == 'tag'
 
@@ -258,4 +262,11 @@ class GekanatorGamesController < ApplicationController
     key = condition[:key].to_s
     !key.start_with?('nico:')
   end
+
+  def game_answer_question_id answer
+    answer['question_id'] ||
+      answer[:question_id] ||
+      answer['questionId'] ||
+      answer[:questionId]
+  end
 end