There was a lively discussion under the following post:

https://lemmy.world/post/53695307

Under which, I received this reply in my inbox:

https://lemmy.world/comment/26567564

Both are now inaccessible, both from the lemmy.world I was accessing them through and after a fruitless search for the original post on their instance. All I see now, which you likely see as well, is an unspecified "Error!"

I perused their mod log but it's like the post (and its comments) no longer exist.

How would I investigate what happened myself, apart from asking their admins/mods? Is this an intentional act or a bug?