Pixar's first sequel almost became the studio's biggest ever disaster

This week, Pixar debuts one of its best ever sequels in the shape of the ambitious, thoughtful Inside Out 2. It's a showcase for how much the studio once considered to be the king of English-speaking animated movies can still bring the goods, despite a very mixed few years of output.

But 25 years ago, Pixar gave us a sequel for the first time. Four years after Toy Story showed the world what computer-animated cinema could do, the studio unveiled a sequel that certainly lived up to its predecessor and, in the view of some fans, even exceeded it.

Things weren't always rosy for the movie, though. There were numerous hurdles that director John Lasseter and the rest of the Pixar team had to vault in order to get their first sequel to the big screen. Not least the fact they kept almost deleting the whole thing.

Initially, there was every chance that Toy Story 2 would go straight to video. Disney was experiencing great success at this time with the likes of Aladdin: The Return of Jafar and The Lion King II: Simba's Pride. The core Pixar team was also very busy with A Bug's Life, so young animator Ash Brannon got the nod as director.

But in 1997, Disney bosses were impressed by the work being done by the secondary team and suggested that this could be a full-scale theatrical feature.

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So by early 1998, Toy Story 2 had become a theatrical proposition. Then, at some point that year, disaster struck in a way that has since become the stuff of legend. In a technical snafu, someone deleted the movie from Pixar's internal servers.

Was Toy Story 2 really deleted?

There was a routine command in the Pixar system used to clear out old sub-directories of waste files. But someone had accidentally deployed it in the root folder for Toy Story 2, meaning the system was slowly deleting every file it could find. The error was noticed when character models started disappearing and folders began to look very slim. Someone pulled the plug on the system in a last-ditch attempt to save it.

When the system came back up, 90% of the movie was gone. Worse still, backup tapes weren't regularly tested and it transpired that they had become full and were overwriting older data. In a post on Quora, Pixar's former chief technical officer Oren Jacob wrote: "It took another several days of the entire crew working on that initial restoral to really understand that the restoral was, in fact, incomplete and corrupt."

Read more: Inside Out 2 is a funny, affecting and inventive Pixar sequel (Digital Spy)

This led to a crisis meeting in which technical director Galyn Susman, who had been working remotely after the birth of her child, revealed she could have a copy of the movie on her home machine. Needless to say, they were very careful about getting that back into the building. Jacob explained to The Next Web that eight people carried it in on a plywood sheet.

Susman's version was a few weeks old, but that wasn't a big deal. What was a big deal is that tens of thousands of files had to be manually checked with human eyes to find inconsistencies and changes. It was pain-staking work that couldn't be done automatically.

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Jacob estimates that the team manually looked at 30,000 files over the course of the weekend. Despite some missing files, everything seemed to render okay. “Where the files went, we don’t know. The fact that it still worked without them is totally unexplainable," said Jacob to The Next Web.

But nobody was too worried about whys and wherefores at this point. They were back in business.

Did Galyn Susman really save Toy Story 2?

There's no doubt that Susman's machine saved the version of Toy Story 2 that existed in 1998. But some months later, the Pixar execs that had been occupied with A Bug's Life saw the state of Toy Story 2, and they weren't happy. Lasseter, who was chief creative officer at Pixar, took over directorial duties and promptly began to completely rebuild the film. The version Susman saved found itself mostly junked in the end anyway.

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Disney refused to move the November 1999 release date, giving everyone at Pixar just nine months to rework and rewrite the movie. Lasseter worked with Pixar's biggest brains, including Andrew Stanton and Pete Docter, to knock Toy Story 2 into shape.

Jacob told The Next Web: "Effectively all animation was tossed. Effectively, all layout was tossed. So all camera work would start from scratch. Lighting was in the film a little bit, but that was tossed as well. We had to build new characters."

Watch: Trailer for Toy Story 2

A herculean effort by everyone involved in the film got it over the line, producing one of the great animated movies of the 20th century in a massively contracted time window. Critics loved Toy Story 2 and it earned a very impressive $511m (£403m) at the worldwide box office. That's success by any measure. It also spawned two more sequels, with another on the way in 2026, as well as a Buzz Lightyear spin-off.

For Jacob, Toy Story 2 was all about the camaraderie. He told The Next Web: "The lasting memory of the experience is the friendships that were formed through that. That journey together through that was one of the community binding together."

Fortunately, all accounts of the production of Inside Out 2 suggests that things went much more smoothly. As far as we know, nobody deleted that one from the systems — deliberately or otherwise.

Inside Out 2 is in UK and US cinemas now.