diff --git a/api/core/plugin/manager/base.py b/api/core/plugin/manager/base.py
index dac6d9d63f..fdc15f633c 100644
--- a/api/core/plugin/manager/base.py
+++ b/api/core/plugin/manager/base.py
@@ -56,7 +56,8 @@ class BasePluginManager:
             line = line.decode("utf-8").strip()
             if line.startswith("data:"):
                 line = line[5:].strip()
-            yield line
+            if line:
+                yield line
 
     def _stream_request_with_model(
         self,
diff --git a/api/core/workflow/nodes/tool/tool_node.py b/api/core/workflow/nodes/tool/tool_node.py
index 73c22bc700..2bcd0b10f2 100644
--- a/api/core/workflow/nodes/tool/tool_node.py
+++ b/api/core/workflow/nodes/tool/tool_node.py
@@ -212,8 +212,8 @@ class ToolNode(BaseNode):
                     chunk_content=message.message.text, from_variable_selector=[self.node_id, "text"]
                 )
             elif message.type == ToolInvokeMessage.MessageType.JSON:
-                assert isinstance(message, ToolInvokeMessage.JsonMessage)
-                json.append(message.json_object)
+                assert isinstance(message.message, ToolInvokeMessage.JsonMessage)
+                json.append(message.message.json_object)
             elif message.type == ToolInvokeMessage.MessageType.LINK:
                 assert isinstance(message.message, ToolInvokeMessage.TextMessage)
                 stream_text = f"Link: {message.message.text}\n"