fix error when survey complete

models/survey_user_input.py

@@ -45,6 +45,10 @@ class SurveyUserInput(models.Model):
             ('question_id', '=', question.id), ])
         if question.question_type == 'upload_file':
             res = self._save_line_simple_answers(question, old_answers, answer)
+        elif not question.question_type:
+            # Fallback for missing question type: silently return empty recordset
+            # raising AttributeError causes RPC_ERROR for the user
+            return self.env['survey.user_input.line']
         else:
             res = super(SurveyUserInput, self)._save_lines(question, answer, comment,
                                       overwrite_existing)