10 Biggest Problems Star Wars: Rogue One Faces (And How Lucasfilm Can Fix Them)
2. Jiang Wen's Massive Spoiler
The Problem: The Star Wars Celebration Rogue One panel definitely wasn't free of hiccups. It there's was conflicting information, the sizzle reel cut out halfway through (no joke) and nobody seemed to know if there was going to be a proper trailer or not. Although those are nothing on Chinese star Jiang Wen dropping some major, third act spoilers.
I'm not going to repeat them here - if you've not heard them yet, you probably don't want to - but essentially during an explanation of his character having a "big gun" he spiralled off into a deep discussion of various characters' arcs, ruining a key part of the film for some of the world's most die-hard Star Wars fans. Oops.
How They Can Fix It: It's out there now, so it's really up to journalists and fans not dropping it casually in discussion without a major spoiler preface. And, to be fair, they seem to be doing it well. There's plenty of people at WhatCulture who have managed to avoid learning what goes down (of whom I'm a little envious).
The best thing everyone on stage did was keep quiet and not draw attention to the spoiler. Kathleen Kennedy was no doubt fuming inside, but never let that show through her Aunt-like demeanour, and with that she may have stopped this becoming the bigger problem it could have been.