For details on how to fix any issues highlighted below, see here.

Update status unknown Could not connect to PyPI to check if your otree package is up to date.
You are using a proper database (Postgres, MySQL, etc).
DEBUG mode is on You should only use DEBUG mode during development and testing of your app. Before launching a study, you should switch DEBUG mode off. To turn off DEBUG mode, set the environment variable OTREE_PRODUCTION to 1.
You are using a server other than runserver.
Sentry not configured Sentry can send you the details of each server error by email. This is necessary because once you have turned off DEBUG mode, you will no longer see Django’s yellow error pages; you or your users will just see generic "500 server error" pages. oTree offers a free Sentry service; you can find the sign-up link in the oTree documentation.
No password protection To prevent unauthorized server access, you should set the environment variable OTREE_AUTH_LEVEL.
Your database appears to be synced.
The worker process is running