A website offering tours of the studios where Harry Potter was filmed has experienced teething trouble on its launch day.
Fans of JK Rowling's magical stories were unable to book tickets for The Making Of Harry Potter on Thursday because of a website error.
Customers were unable to complete the booking process when they logged on to the Warner Brothers Studio Tour website - www.wbstudiotour.co.uk.
The attraction in Leavesden, near Watford, will be one of the largest studio tours in Europe when it opens next spring.
The three-hour tours will feature original sets, including the Hogwarts Great Hall, the Gryffindor Common Room and headmaster Dumbledore's office, plus costumes, props and effects used in all eight movies.
The 150,000 sq ft studio is the size of three football pitches and boasts two sound stages.
Warner Brothers, which runs the studios, said it was aware there had been some problems and blamed the volume of traffic to the site for the glitch.
Fans vented their frustration on social networking site Twitter, with some saying it took two hours to book.
One said: "How can the website selling Harry Potter studio tour tickets not be expecting mega traffic? No need for Divination classes to predict that."
Another said: "Harry needs to get his magic wand out and fix the Warner Bros website, trying to book tickets to the Harry Potter studio tour is impossible!"