I can help on this mate. While we mods are active on the forums, we do “patrol” the item graveyard as well, so do reviewers, so do the majority of community oriented staff. There are cases where authors simply decide it’s no longer their cup of tea to be authors and just abandon profiles, while rare, it’s sad.
I strongly recommend you send any dead file to Envato Authors Help and Support. The procedure for this is simple. There can be cases where the Author forgot to pay his hosting subscription or is just having server issues, but, staff will attempt to get in touch with the respective author.
If the author doesn’t reply / take action to “revive” his dead items he’s items will be disabled. In case you see buyers in these situations, please send them over to Envato Buyerst Help and Support, as these do fall under refundable issues, since, a buyer is entitled to 6 month included support, an abandoned item means that isn’t granted.
Although these cases are rare, be sure to report them to support! You don’t need to be a Moderator or Staff member to help keep Envato clean! (remember, there are a handful of reviewers and a few million items, kind of hard to keep up with them all, haha! )
Last year I reported a couple cases, and they were swiftly dealt with (under 2-4 days). Cheers mate! 