Some festival-goers "collapsed" after long queues led to crowds pushing through security gates at a London festival.
Videos and photos on social media appear to show a rush through the gates and a huge queue of people trying to get into We Are FSTVL.
Some ticketholders told Radio 1 Newsbeat they left the site without getting into the event.
Organisers have apologised for the problems.
The two-day festival is held in east London and its Saturday line-up included Chase and Status, Bugzy Malone and CamelPhat.
Eyewitnesses say a lack of wristbands meant that people had to queue in hot temperatures in Upminster - which led to people charging past staff and into the event.