The instance is down. Every instance copies the posts from the other instances when at least one person subscribes to it. So what you see is just the remnants of the instance on your instance.
Lemmy Support
Support / questions about Lemmy.
It went down without any indications as to why AFAIU, as in no admin piped up anywhere about what was going on. So either something awful happened, or they just weren’t up for running an instance anymore and didn’t want to bother with the hassle of explaining that to others.
Seems like it, i never visit that community before so it wouldn't load for me with my current instance.
It's cached content in the fediverse. That's the whole point, the instance may be gone, but the content lives on through instance sync.
And yes, you can create a post there, but that post can be viewed only by members of your instance, since that instance (lemmy.film) is not there to actually try and sync other instances with the created content. Basically, it's a post created on your instance, and then the instance tries to push that new content to the instance and comm you're posting to, but since it doesn't exist any more, the post is placed in the right place, but never actually synced with other instances.