Diablo 4 Season 12 has already produced no shortage of bug reports, and now another smaller but still nasty one is making the rounds on Blizzard’s own forums: a player says a Forgotten Remains Nightmare Dungeon event tied to Subo can get stuck because one enemy will not die.
The report showed up in Blizzard’s PC Bug Report section on March 21 under the very subtle title “Forgotten Remains NMD Event with Subo Bugged - Enemy Will NOT Die! Fix Your Broken Game Blizzard!” That thread is now also visible in the current bug-report listings, which is enough to treat it as a fresh live issue players are surfacing during the current Season 12 cycle.
What the player is reporting
The core complaint is simple: during a Forgotten Remains Nightmare Dungeon event involving Subo, one enemy allegedly becomes impossible to kill, which appears to trap or soft-lock the encounter. The thread itself frames this as another example of older unresolved bugs carrying over while new Season 12 problems pile on top.
At the moment, this should be treated as a player bug report, not as a fully confirmed Blizzard-wide incident. The public evidence here shows a fresh report in the official bug forum and current visibility in Blizzard’s listings, but not a blue-post confirmation explaining the cause or offering a fix timeline.
Why this kind of bug matters even if it looks small
On paper, one unkillable enemy in one dungeon event sounds like a niche problem. In practice, these are exactly the bugs players hate most in an ARPG.
A tuning issue can feel annoying. A soft-lock feels like theft. If a run stops because one enemy refuses to die, players do not just lose efficiency. They lose time, momentum, and trust that the content will actually resolve correctly once they engage with it. That is especially frustrating in seasonal content where players are repeatedly pushing dungeons for rewards, progress, or materials. This is an inference based on the reported behavior and the role dungeon events play in Diablo 4’s loop.
It fits an existing Season 12 pattern
This is also not landing in a vacuum.
Blizzard’s latest Diablo IV forum pages still show active player discussion around missing rewards, Rank progression failures, PvP problems, lag, and other bug reports. The Forgotten Remains/Subo complaint sits inside that broader environment, where even smaller encounter-level issues can feel bigger because players are already primed to expect friction.
There is also a separate community-maintained Season 12 List of Known Bugs thread that has become a gathering point for reports ranging from group-play problems to dungeon and encounter issues. The Forgotten Remains/Subo bug appears inside that discussion as well, which suggests it is at least getting noticed by the part of the player base already tracking Season 12 problems closely.
The bigger issue is reliability, not just one monster
That is what makes this article worth writing.
The real story is not “one monster bugged out.” The real story is that Season 12 keeps collecting reports where content does not complete the way players expect. Sometimes it is progression not counting. Sometimes it is rewards not being granted. Here, it is an encounter that reportedly cannot finish because one enemy will not die. They are different bugs, but they all point at the same broader player concern: can the season’s content be trusted to function cleanly? This last point is an inference based on the pattern of current reports.
No public fix yet, but it is the kind of report Blizzard will want to squash quickly
Based on the sources reviewed here, there is not yet a public Blizzard confirmation that this specific Forgotten Remains/Subo issue is fixed or formally recognized in patch notes. That means the cleanest framing is still cautious: this is a fresh official-forum player report about a Nightmare Dungeon event soft-lock in Season 12.
If it stays isolated, it may never become more than a minor footnote. But if more players run into the same event behavior, it becomes exactly the sort of bug that travels fast because the complaint is so easy to understand: I did the dungeon, but the game would not let the fight end. And in Diablo, that usually gets attention a lot faster than one more awkward tooltip.
