I've just updated to Odoo 18. For some reason my attendees can't register anymore on the registration website for an event. This error occurs:

UncaughtPromiseError > TypeError

Uncaught Promise > modalEl.querySelector is not a function

Occured on the-reef.odoo.com on 2025-03-24 15:56:29 GMT

TypeError: modalEl.querySelector is not a function

    at Class._onClick (https://the-reef.odoo.com/web/assets/1/c87196b/web.assets_frontend_lazy.min.js:9330:101)

How can I resolve this? Everything was set up right for this event, but people can't register anymore. If somebody can help me out, it would be very much appreciated.