Couldn’t start the app because 'http://127.0.0.1:7860/gradio_api/startup-events' failed (code 502)

* Running on local URL: http://127.0.0.1:7860
Traceback (most recent call last):
File "C:\Users\Administrator\framepack_cu126_torch26\webui\demo_gradio.py", line 404, in
block.launch(
File "C:\Users\Administrator\framepack_cu126_torch26\system\python\lib\site-packages\gradio\blocks.py", line 2685, in launch
raise Exception(
Exception: Couldn’t start the app because 'http://127.0.0.1:7860/gradio_api/startup-events' failed (code 502). Check your network or proxy settings to ensure localhost is accessible.

执行run.bat之后就一直报这个错误，看了下block.py文件中第2685行是
if not wasm_utils.IS_WASM:
# Cannot run async functions in background other than app's scope.
# Workaround by triggering the app endpoint
resp = httpx.get(
f"{self.local_api_url}startup-events",
verify=ssl_verify,
timeout=None,
)
if not resp.is_success:
raise Exception(
f"Couldn’t start the app because '{resp.url}' failed (code {resp.status_code}). Check your network or proxy settings to ensure localhost is accessible."
)
显卡是4090 48GB版本，驱动版本572.70，cuda版本是12.4，运行环境win11，python3.12.7
webui下已执行更新requirements.txt

Reproduce the failure with run.bat, then inspect webui/demo_gradio.py around line 404 and the referenced system/python/lib/site-packages/gradio/blocks.py line 2685. Check the installed requirements.txt environment and the local startup endpoint; done means the app launches without the 502 startup-events error.

Written by the indexing model from the issue text.