A 404 on a booking page can occur in the following cases
The booking page has been deleted.
The owner of the booking page is no longer available.
Cases in which the owner of the booking page is no longer available
If a member is deleted from the user management page and the member is the owner of the booking page, the owner of the booking page will disappear and the booking page will display a 404.
Edit booking page > Participating members
If the owner is set to the member's permissions, the page will be displayed normally.