FastApi uvicorn server not connecting to localhost

Question

I am trying FASTAPI with the code below and localhost is not reachable with 127.0.0.1:8000 or localhost:8000 also. Tried setting with different port numbers also.

At the end it says

NameError: name '_TypeAliasForm' is not defined

This is on windows 10 with python 3.10

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def root():
    return {"message": "Hello World"}

PS G:\pyproj\fastapiex> uvicorn main:app --reload
←[32mINFO←[0m:     Will watch for changes in these directories: ['G:\\pyproj\\fastapiex']
←[32mINFO←[0m:     Uvicorn running on ←[1mhttp://127.0.0.1:8000←[0m (Press CTRL+C to quit)
←[32mINFO←[0m:     Started reloader process [←[36m←[1m6936←[0m] using ←[36m←[1mwatchgod←[0m
Process SpawnProcess-1:
Traceback (most recent call last):
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\multiprocessing\process.py", line 315, in _bootstrap
    self.run()
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\multiprocessing\process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\uvicorn\subprocess.py", line 76, in subprocess_started
    target(sockets=sockets)
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\uvicorn\server.py", line 68, in run
    return asyncio.run(self.serve(sockets=sockets))
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\asyncio\runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\asyncio\base_events.py", line 641, in run_until_complete
    return future.result()
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\uvicorn\server.py", line 76, in serve
    config.load()
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\uvicorn\config.py", line 448, in load
    self.loaded_app = import_from_string(self.app)
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\uvicorn\importer.py", line 21, in import_from_string
    module = importlib.import_module(module_str)
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1049, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1026, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1005, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 698, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 832, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File ".\main.py", line 1, in <module>
    from fastapi import FastAPI
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\fastapi\__init__.py", line 7, in <module>
    from .applications import FastAPI as FastAPI
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\fastapi\applications.py", line 3, in <module>
    from fastapi import routing
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\fastapi\routing.py", line 20, in <module>
    from fastapi import params
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\fastapi\params.py", line 4, in <module>
    from pydantic.fields import FieldInfo, Undefined
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\pydantic\__init__.py", line 2, in <module>
    from . import dataclasses
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\pydantic\dataclasses.py", line 3, in <module>
    from .class_validators import gather_all_validators
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\pydantic\class_validators.py", line 8, in <module>
    from .errors import ConfigError
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\pydantic\errors.py", line 5, in <module>
    from .typing import display_as_type
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\pydantic\typing.py", line 23, in <module>
    from typing_extensions import Annotated, Literal
  File "c:\users\jsl\appdata\local\programs\python\python310\lib\site-packages\typing_extensions.py", line 1786, in <module>
    @_TypeAliasForm
NameError: name '_TypeAliasForm' is not defined