과제 404에러

.submit.bat cvio19692

∙ Session token prefix: 32fe457c60

✔ [0] Session 32fe457c60 is ready.

Uploading files: 100%|█████████████| 5.69k/5.69k [00:00<00:00, 158kbytes/s, file=arithmetic_unit_test.py]

✔ [0] Uploading done.

✘ [0] BackendClientError('Request to the API endpoint has failed.nCheck your network connection and/or the server status.nError detail: WSServerHandshakeError("404, message=\'Invalid response status\'")')

위와 같은 오류가 과제 제출시 뜨는데 해결 방법이 뭔가요..?