Ticketmaster apologised to JK Rowling fans over the weekend after huge demand for the opening of registration in the US for ‘Harry Potter and the Cursed Child’ led to the website crashing and sales being put back a week.

The registration process for the Broadway show opened on Sunday, but a series of glitches involving the Verified Fan system means tickets will now go on sale on October 18, a week later than originally scheduled.

Fans were less than impressed with Ticketmaster’s sales procedure, with many complaining that they were repeatedly forced to enter details. Mark Churaman tweeted: “The site to register to purchase tickets for Harry Potter and the Cursed Child in NYC has crashed. Lord help us when they go on sale.”

A message on the Harry Potter section of Ticketmaster’s site read: “We’ll be back soon. Our site is currently unavailable due to an extreme amount of registration activity; please check back soon.”

The company also tweeted: “We apologise for this morning’s #CursedChildNYC registration issues. We are experiencing unprecedented demand and working to resolve.”

The show begins previews at the Lyric Theatre on March 16, 2018, with an official opening night of April 22.

The Ticketmaster Verified Fan registration period runs through October 5 with verified fans receiving access codes to purchase tickets.