The Avengers weren't prepared for supervillain Thanos and it appears that some online ticket sites weren't ready for Avengers: Endgame because of the rush for the much-awaited superhero movie.

Pre-sale tickets for "Avengers: Endgame", the latest film from Marvel Studios which opens on April 26, went on sale on Tuesday morning, prompting fans to flock to sites like Fandango and AMC to grab their tickets, reports cnn.com.