Microsoft had plans to demo its HoloLens 2 headsets at its annual Build developer conference.

The keyword here is "had," though, as things didn't exactly go as planned, and in the end, the company couldn't do the presentation.

Microsoft's HoloLens 2 Demo Fail

At the event, space historian and author of A Man on the Moon Andy Chaikan and Industrial Light and Magic's Chief Creative Officer John Knoll went onstage wearing HoloLens 2 headsets. As Knoll explained, they're going to recreate the Apollo 11 moon landing mission using Unreal Engine and the mixed reality technology of Microsoft, who collaborated with Epic Games for the demo.

However, things quickly went awry. As Chaikan opened his arms in the air to supposedly cue the appearance of the Saturn V moon rocket, an ambient space music started playing in the background, and the camera panned to show the entire length of air above the two presenters — no rocket, no nothing.

"Well, it seems doing a live demo is actually harder than landing on the moon," Chaikan said, thanking the audience for their time before stepping off the stage.

Moments after, Microsoft CEO Satya Nadella took the stage to continue the show, without even acknowledging the flub that happened beforehand.

Hit up the video below to see it in motion. Things start getting interesting at the 52:50 mark.

What If Things Went Well?

The official YouTube channel of Unreal Engine uploaded a clip of a rehearsal of the demo. The video shows what could've been if there hadn't been any technical difficulties.

Needless to say, it would've been impressive if all went smoothly. As The Verge explains, Unreal Engine has a pixel streaming feature that lets high-quality images and such to be streamed to the HoloLens 2 from PCs equipped with graphics cards to render them. The headset needs this since it doesn't have a powerful GPU to work with.

Build 2019 was the perfect place to show off the technology, but if nothing else, the onstage blunder made the event all the more memorable.