diff --git a/api/core/app/apps/advanced_chat/generate_task_pipeline.py b/api/core/app/apps/advanced_chat/generate_task_pipeline.py
index 2875c86329..a83000a0bc 100644
--- a/api/core/app/apps/advanced_chat/generate_task_pipeline.py
+++ b/api/core/app/apps/advanced_chat/generate_task_pipeline.py
@@ -487,7 +487,7 @@ class AdvancedChatAppGenerateTaskPipeline(BasedGenerateTaskPipeline, WorkflowCyc
                     value = None
                     for key in value_selector[1:]:
                         if not value:
-                            value = outputs.get(key)
+                            value = outputs.get(key) if outputs else None
                         else:
                             value = value.get(key)