I built an agent containing the mcp tools by referring to the example in the document, but a bug occurred when running it with adk web: RuntimeError: error getting root agent.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////
Operation Environment:
Windows 11 24H2 64bit
Python version 3.13.2
google-adk version 0.3.0

aiohappyeyeballs 2.6.1
aiohttp 3.11.18
aiosignal 1.3.2
annotated-types 0.7.0
anyio 4.9.0
attrs 25.3.0
authlib 1.5.2
cachetools 5.5.2
certifi 2025.1.31
cffi 1.17.1
charset-normalizer 3.4.1
click 8.1.8
colorama 0.4.6
cryptography 44.0.2
deprecated 1.2.18
distro 1.9.0
docstring-parser 0.16
fastapi 0.115.12
filelock 3.18.0
frozenlist 1.6.0
fsspec 2025.3.2
google-adk 0.3.0
google-api-core 2.24.2
google-api-python-client 2.168.0
google-auth 2.39.0
google-auth-httplib2 0.2.0
google-cloud-aiplatform 1.90.0
google-cloud-bigquery 3.31.0
google-cloud-core 2.4.3
google-cloud-resource-manager 1.14.2
google-cloud-secret-manager 2.23.3
google-cloud-speech 2.32.0
google-cloud-storage 2.19.0
google-cloud-trace 1.16.1
google-crc32c 1.7.1
google-genai 1.12.1
google-resumable-media 2.7.2
googleapis-common-protos 1.70.0
graphviz 0.20.3
greenlet 3.2.1
grpc-google-iam-v1 0.14.2
grpcio 1.71.0
grpcio-status 1.71.0
h11 0.16.0
httpcore 1.0.9
httplib2 0.22.0
httpx 0.28.1
httpx-sse 0.4.0
huggingface-hub 0.30.2
idna 3.10
importlib-metadata 8.6.1
jinja2 3.1.6
jiter 0.9.0
jsonschema 4.23.0
jsonschema-specifications 2024.10.1
litellm 1.67.0.post1
markupsafe 3.0.2
mcp 1.6.0
multidict 6.4.3
numpy 2.2.5
openai 1.75.0
opentelemetry-api 1.32.1
opentelemetry-exporter-gcp-trace 1.9.0
opentelemetry-resourcedetector-gcp 1.9.0a0
opentelemetry-sdk 1.32.1
opentelemetry-semantic-conventions 0.53b1
packaging 25.0
propcache 0.3.1
proto-plus 1.26.1
protobuf 5.29.4
pyasn1 0.6.1
pyasn1-modules 0.4.2
pycparser 2.22
pydantic 2.11.3
pydantic-core 2.33.1
pydantic-settings 2.9.1
pyparsing 3.2.3
python-dateutil 2.9.0.post0
python-dotenv 1.1.0
pyyaml 6.0.2
referencing 0.36.2
regex 2024.11.6
requests 2.32.3
rpds-py 0.24.0
rsa 4.9.1
shapely 2.1.0
six 1.17.0
sniffio 1.3.1
sqlalchemy 2.0.40
sse-starlette 2.3.3
starlette 0.46.2
tiktoken 0.9.0
tokenizers 0.21.1
tqdm 4.67.1
typing-extensions 4.13.2
typing-inspection 0.4.0
tzdata 2025.2
tzlocal 5.3.1
uritemplate 4.1.1
urllib3 2.4.0
uvicorn 0.34.2
websockets 15.0.1
wrapt 1.17.2
yarl 1.20.0
zipp 3.21.0

The detailed code is as follows:
////////////////////////////////////////////////////////////////////////////////////////////////////////////////
init.py:

from . import agent

////////////////////////////////////////////////////////////////////////////////////////////////////////////////
agent.py:

import os
from dotenv import load_dotenv
from google.adk.models.lite_llm import LiteLlm
from google.adk.agents.llm_agent import LlmAgent
from google.adk.tools.mcp_tool.mcp_toolset import MCPToolset, SseServerParams, StdioServerParameters

load_dotenv()

async def get_tools_async():
  """Gets tools from the File System MCP Server."""
  print("Attempting to connect to MCP Filesystem server...")
  tools, exit_stack = await MCPToolset.from_server(
      # Use StdioServerParameters for local process communication
      connection_params=StdioServerParameters(
          command='npx.cmd', 
          args=["-y",   
                "@modelcontextprotocol/server-filesystem",
                "E:/sandbox"],
      )
  )
  print("MCP Toolset created successfully.")
  # MCP requires maintaining a connection to the local MCP Server.
  # exit_stack manages the cleanup of this connection.
  return tools, exit_stack

# LiteLLM uses different ENV variables for OpenAI and OpenTelemetry fields.
os.environ["OPENAI_API_BASE"] = os.getenv("SILI_BASE_URL")  
os.environ["OPENAI_API_KEY"] = os.getenv("SILI_API_KEY")

async def create_agent():
  """Gets tools from MCP Server."""
  tools, exit_stack = await get_tools_async()
  
  agent = LlmAgent(
      model=LiteLlm(model="openai/Pro/deepseek-ai/DeepSeek-V3-1226"), 
      name='filesystem_assistant',
      instruction='Help user interact with the local filesystem using available tools.',
      tools=tools, # Provide the MCP tools to the ADK agent
  )
  return agent, exit_stack

root_agent = create_agent()

////////////////////////////////////////////////////////////////////////////////////////////////////////////////
Error information:

2025-04-25 11:37:54,069 - INFO - _client.py:1025 - HTTP Request: GET https://raw.githubusercontent.com/BerriAI/litellm/main/model_prices_and_context_window.json "HTTP/1.1 200 OK"
Attempting to connect to MCP Filesystem server...
2025-04-25 11:37:56,002 - ERROR - fast_api.py:637 - Error in event_generator: error getting root agent,
Traceback (most recent call last):
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\mcp\client\stdio\win32.py", line 72, in create_windows_process
process = await anyio.open_process(
^^^^^^^^^^^^^^^^^^^^^^^^^
...<8 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\anyio_core_subprocesses.py", line 190, in open_process
return await get_async_backend().open_process(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<11 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\anyio_backends_asyncio.py", line 2561, in open_process
process = await asyncio.create_subprocess_exec(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<5 lines>...
)
^
File "E:\Application11\Python\Python313\Lib\asyncio\subprocess.py", line 224, in create_subprocess_exec
transport, protocol = await loop.subprocess_exec(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<3 lines>...
stderr=stderr, **kwds)
^^^^^^^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\asyncio\base_events.py", line 1794, in subprocess_exec
transport = await self._make_subprocess_transport(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
protocol, popen_args, False, stdin, stdout, stderr,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
bufsize, **kwargs)
^^^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\asyncio\base_events.py", line 539, in _make_subprocess_transport
raise NotImplementedError
NotImplementedError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\cli\fast_api.py", line 782, in _get_root_agent_async
agent, exit_stack = await root_agent
^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai\multi_tool_agent\filesystem_agent\agent.py", line 41, in create_agent
tools, exit_stack = await get_tools_async()
^^^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai\multi_tool_agent\filesystem_agent\agent.py", line 18, in get_tools_async
tools, exit_stack = await MCPToolset.from_server(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<10 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_toolset.py", line 223, in from_server
await async_exit_stack.enter_async_context(toolset)
File "E:\Application11\Python\Python313\Lib\contextlib.py", line 668, in enter_async_context
result = await _enter(cm)
^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_toolset.py", line 258, in aenter
raise e
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_toolset.py", line 255, in aenter
await self._initialize()
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_toolset.py", line 229, in _initialize
self.session = await self.session_manager.create_session()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_session_manager.py", line 132, in create_session
return await MCPSessionManager.initialize_session(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<3 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\tools\mcp_tool\mcp_session_manager.py", line 173, in initialize_session
transports = await exit_stack.enter_async_context(client)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\contextlib.py", line 668, in enter_async_context
result = await enter(cm)
^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\contextlib.py", line 214, in aenter
return await anext(self.gen)
^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\mcp\client\stdio_init.py", line 113, in stdio_client
process = await create_platform_compatible_process(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<9 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\mcp\client\stdio_init.py", line 210, in _create_platform_compatible_process
process = await create_windows_process(command, args, env, errlog, cwd)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\mcp\client\stdio\win32.py", line 85, in create_windows_process
process = await anyio.open_process(
^^^^^^^^^^^^^^^^^^^^^^^^^
[command, *args], env=env, stderr=errlog, cwd=cwd
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\anyio_core_subprocesses.py", line 190, in open_process
return await get_async_backend().open_process(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<11 lines>...
)
^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\anyio_backends_asyncio.py", line 2561, in open_process
process = await asyncio.create_subprocess_exec(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<5 lines>...
)
^
File "E:\Application11\Python\Python313\Lib\asyncio\subprocess.py", line 224, in create_subprocess_exec
transport, protocol = await loop.subprocess_exec(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<3 lines>...
stderr=stderr, **kwds)
^^^^^^^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\asyncio\base_events.py", line 1794, in subprocess_exec
transport = await self._make_subprocess_transport(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
protocol, popen_args, False, stdin, stdout, stderr,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
bufsize, **kwargs)
^^^^^^^^^^^^^^^^^^
File "E:\Application11\Python\Python313\Lib\asyncio\base_events.py", line 539, in _make_subprocess_transport
raise NotImplementedError
NotImplementedError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\cli\fast_api.py", line 625, in event_generator
runner = await _get_runner_async(req.app_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\cli\fast_api.py", line 796, in _get_runner_async
root_agent = await _get_root_agent_async(app_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "E:\uv_venv2\google_ai.venv\Lib\site-packages\google\adk\cli\fast_api.py", line 786, in _get_root_agent_async
raise RuntimeError(f"error getting root agent, {e}") from e
RuntimeError: error getting root agent,