The story goes that after filming the (what was supposed to be,) epic superhero team up film Justice League director Zack Snyder walked away. It was during post production and after Zack walked away Joss Whedon stepped in to finish the movie. The film was critically panned and it wasn’t very enjoyable to a lot of fans as well.
Zack Snyder was also behind the Superman reboot film Man of Steel. That move was supposed to be the beginning of the DC Comics film universe. Similar to how Iron Man launched the Marvel film universe. Now Warner Bros. (who owns the movie rights to DC’s comic book characters,) gave Mr. Snyder the reigns and will be releasing this cut of the film as a 4 hour movie on HBO Max March 18th. We also get to see Jared Leto’s Joker who was not in the theatrical release.