This has occurred due to a bug that is currently being investigated. This occasionally happens after a participant/captain makes a change to their personal/team page. In certain conditions, it removes the custom layout and it is no longer visible in the Layout dropdown menu on the backend. The layout can be restored by clicking "Replace with Default Page" which will bring back the layout. You'll want to make sure you save any images or content before replacing it with default as it will remove any changes made by the participant before that time.