fix but

app/helpers/exercises_helper.rb

@@ -413,9 +413,8 @@ module ExercisesHelper
           score2 += 0.0
         end
       elsif q.question_type == 5   #实训题时，主观题这里不评分
-        if answers_content.present?
         q.exercise_shixun_challenges.each do |exercise_cha|
-            game = Game.user_games(user.id,exercise_cha.challenge_id).first  #当前用户的关卡
+          game = Game.user_games(user.id,exercise_cha.challenge_id)&.first  #当前用户的关卡
           if game.present?
             exercise_cha_score = 0.0
             answer_status = 0
@@ -423,7 +422,7 @@ module ExercisesHelper
               exercise_cha_score = exercise_cha.question_score #每一关卡的得分
               answer_status = 1
             end
-              ex_shixun_answer_content = answers_content.where(exercise_shixun_challenge_id: exercise_cha.id)
+            ex_shixun_answer_content = answers_content&.where(exercise_shixun_challenge_id: exercise_cha.id)
             if ex_shixun_answer_content.blank?  #把关卡的答案存入试卷的实训里
               cha_path = challenge_path exercise_cha.challenge.path
               game_challenge = game.game_codes.search_challenge_path(cha_path).first
@@ -446,12 +445,11 @@ module ExercisesHelper
               ex_shixun_answer_content.first.update_column('score',exercise_cha_score)
             end
             score5 += exercise_cha_score
-            end
-          end
           else
             score5 += 0.0
           end
         end
+      end
       user_scores = answers_content.present? ? answers_content.score_reviewed.pluck(:score).sum : 0.0
       if user_scores > 0
         stand_answer = 1