运行FastAPI时出现Access Denied权限错误求助

我刚开始使用FastAPI，运行官网提供的示例代码时遇到了Access Denied权限错误。我使用Windows系统，且拥有所有相关文件夹的访问权限，不清楚错误原因。

错误截图：

错误栈信息：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\x\AppData\Local\Programs\Python\Python310\lib\multiprocessing\spawn.py", line 107, in spawn_main
    new_handle = reduction.duplicate(pipe_handle,
  File "C:\Users\x\AppData\Local\Programs\Python\Python310\lib\multiprocessing\reduction.py", line 79, in duplicate
    return _winapi.DuplicateHandle(
PermissionError: [WinError 5] Access is denied

使用的示例代码：

from typing import Union
from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()

class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "world"}

@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}

@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id, "item_price": item.price}

望各位能提供帮助，谢谢！

内容的提问来源于stack exchange，提问作者bOB