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 also assume it’s an expired certificate.
See, this is what happens when certificates are not renewed automatically.
The article says the projectos are discontinued. That’s probably the reason no one is monitoring these certs.
Another glorious benefit of DRM.