From the article:
When we went to our seats, the wait staff let us know that despite the fact that the previews were playing, we wouldn’t know until the movie actually started whether we could see the film or not. If it didn’t work, the screen would just turn black. Luckily, the film went through without a hitch.
I mean, my home is filled with ancient laptops that we use until they explode, its a pretty common occurrence when trying to watch something streaming the ads would load just fine but the actual show wouldn't actually load. So... shrug