diff --git a/ai/views/oj.py b/ai/views/oj.py
index eea18c2..dc0117b 100644
--- a/ai/views/oj.py
+++ b/ai/views/oj.py
@@ -219,6 +219,13 @@ class AIDetailDataAPI(APIView):
         end = request.GET.get("end")
         username = request.GET.get("username")
 
+        if not start or not end:
+            return self.error("参数 start 和 end 不能为空")
+        if not parse_datetime(start):
+            return self.error("start 格式无效，请使用 ISO 8601 格式")
+        if not parse_datetime(end):
+            return self.error("end 格式无效，请使用 ISO 8601 格式")
+
         user = request.user
         if username and request.user.is_super_admin():
             try:
diff --git a/flowchart/tasks.py b/flowchart/tasks.py
index 98b4f38..071ea01 100644
--- a/flowchart/tasks.py
+++ b/flowchart/tasks.py
@@ -1,7 +1,10 @@
 import json
+import logging
 import time
 
 import dramatiq
+
+logger = logging.getLogger(__name__)
 from django.db import transaction
 from django.utils import timezone
 
@@ -96,6 +99,7 @@ def evaluate_flowchart_task(submission_id):
         )
         
     except Exception as e:
+        logger.exception("evaluate_flowchart_task failed for submission %s", submission_id)
         if submission is not None:
             submission.status = FlowchartSubmissionStatus.FAILED
             submission.save()
diff --git a/oj/production_settings.py b/oj/production_settings.py
index d6786e1..467b35b 100644
--- a/oj/production_settings.py
+++ b/oj/production_settings.py
@@ -16,7 +16,7 @@ REDIS_CONF = {
     "port": get_env("REDIS_PORT", "6379"),
 }
 
-DEBUG = True
+DEBUG = False
 
 ALLOWED_HOSTS = ["*"]