[FIXED] [PvE] Combat bugs caused by invisible/unspecified NPCs

[Midius]

WoW Freakz link: https://www.wow-freakz.com/npc_finder.php?npc=120586&&name=fel-bunny

Bug description: After killing some mobs in Nath'raxas Hold (I was using divine storm) I was still in combat, after running away something started hitting me. I'm pretty sure I shouldn't be able to aggro this guy. The bug is easily reproducible, go to Nath'raxas Hold, Krokuun on the small fel lava lake @ 50, 33, use divine storm/remorseless winter/etc. and see for yourself.

This brings me to the actual problem and why I'm repporting it: fixing aggro/targeting for all trigger/unspecified NPCs (at least in instances)

Explanation: Of course that in-world this is just a nuisance (running away 100 yds for example would solve it), but what I suspect is that when this happens in a raid it would cause the well-known "combat bug" many have seen that appears like a "random bug" but it isn't. The Emerald Nightmare combat bugs/Goroth combat bug well-known on 7.2.5 (being in combat after you kill a boss) are examples that I've suspected for a long time as having a similar cause since nothing else can explain them. There is a lot of correlative evidence:

- in dungeon/raids there are many such "special NPCs" on which you will keep aggro indefinitely (because it's an instance) and can't get rid of it
- it's almost impossible to find what causes it in raid instances, since you are with 10-20 other players someone else has aggro most of the time
- it invariably takes the form of someone who is in combat (but nobody can explain it as you aren't in combat with trash or doing anything else)
- many times there is the following animation: you are "hit by something" but there is nothing there (since of course the NPC is invisible and you can't even target it)

It wastes a lot of time because if it happens in an instance then you can't use food, use flask or summon anyone else - the only way to fix it is running away from the group OR wiping which does remove aggro but again wastes time (which is more evidence for this if you needed it).

I would be very happy if this would bring a fix to this issue which has been going on for some time on 7.2.5 without being reported, because it's very hard to bring proof that you shouldn't be in combat.

Note: Another correlated issue was that of boss adds (if these would also count as "adds") not despawning correctly, because if some of these spawn in a boss fight and won't despawn the same thing can happen; this is a side problem caused by bosses (and their adds) not despawning when you wipe, this would require a separate bug report, I mentioned it since it's part of the problem.

Proof: Screenshot (see combat log)

[Power]

Fixed this one, live after restart.

Raids and dungeons were re-worked, the issues stated above should not happen anymore but there might still be isolated cases like this, please open a new bug report if you encounter any.