Detectives are appealing for information about the stabbing.
A coroner in Chelmsford rules Scott Messenger's death in St Osyth was an accident.
Jack, 15, says the service meant so much to him and to local people.
Visitors can use augmented reality to see re-enactments of stories from the 16th and 17th centuries.
A man is taken to hospital with serious injuries which are not thought to be life-changing, police say.
A man has been taken to hospital having sustained serious injuries, a police force says.
The 15th Century building is part of an ancient estate transformed into a luxury wedding venue.
Essex Police is urging anyone who might have information to come forward and help with inquiries.
The £12m scheme aims to protect 3,000 homes and businesses in the area from tidal flooding.
