Ad server keeps restarting on docker

[khalidmaquilang]

i am having this error

Traceback (most recent call last):

  File "<frozen runpy>", line 198, in _run_module_as_main

  File "<frozen runpy>", line 88, in _run_code

  File "/app/liteads/ad_server/main.py", line 16, in <module>

    from liteads.ad_server.routers import ad, event, health

  File "/app/liteads/ad_server/routers/event.py", line 8, in <module>

    from liteads.ad_server.services.event_service import EventService

  File "/app/liteads/ad_server/services/event_service.py", line 16, in <module>

    from liteads.models import AdEvent, EventType

ImportError: cannot import name 'AdEvent' from 'liteads.models' (/app/liteads/models/__init__.py)