Your web browser will download Caterbook and store it locally to speed up your access.
Sometimes when we deploy changes, your local version of Caterbook doesn't match what we have on our servers and this can lead to issues. You need to clear your old cached version, and download the latest version.
You can do this easily by launching a private browsing session and logging into Caterbook once.
From the top right hand corner of your browser click the 3 dots or lines and launch a new private browsing session.
Type in https://app.caterbook.net and login with your details.
The cached version will be replaced by the new one and you can go back to loading Caterbook in the usual way.