Mob missing MoveToPawn packet if attacked by long range magic with abnormal effect

[ShinichiYao]

Test with skill: Dark Vortex(1343), once mob get the debuff effect it teleport to you. Exist very long time.

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Video Here

Old Commit history here

This is Packet record:

Debuff not affected

Debuff affected

Also happens on grand boss, missing movement animation just teleport from place to place.

Position Related Issue:

Position on Target Selected

Position on Meele Attack

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[FinalDestination]

i notice this bug is not only for monsters when i fear a player happend same

[ShinichiYao]

I finally found out why @Zoey76 wont notice this problem. Because All of us has made a change at aggroRange of NPC to a lower number. With original code mob will see you befor you start to attack.

[FinalDestination]

this is serious someone need to fix it its 2 years bug

[MaGa]

This happen with Curse Gloom too.

[Nova Kilem]

Any chance for this ever being fixed? Happens with fear, debuffs that affects move speed and some other debuffs as well.

[Nova Kilem]

I have spent quite a few hours with investigating this issue and after countles tests, I can confirm the following for sure:

1: This happens with skills that have 2 or more effects where one of the effects is continouous effect (Debuffs, DoT, or mana damage over time, TargetMe). and the other is instant (PhysicalAttack or MagicalAttack , PhysicalSoulAttack etc, or GetAgro. Other instant effect skills like dispelbyslot, etc do not cause skip/lag).

2:The only effect which also makes the mobs skip in itself is FEAR. Although by reducing the ticks to 1 from 5 in the Fear.java effect handler seems to solve the issue, although there's still a half second skip before the mob start running away.

3: Mobs lag/skip in the following cases: If it's intention is active (AKA just standing still and affected by the type of skills I mentioned above) or if has attack intention and it's actually hitting you (in case of fear only). Mob's with MOVE_TO intention or ATTACK intention that are still moving towards the target are unaffected.

So, in a nutshell, this bug has something to do with skill effects or hp reduction when affected by multiple effect skills that deal damage or change the AI intention, instead of missing movetolocation packets or movetopawn. When instant and continouos effects applied at once they either mess up the movement ai or something that is realated to the ai tasks.

[ShinichiYao]

Yes, a very old bug. I think everyone has his own way to fix this after years.

[Nova Kilem]

That may be true, but this is still a pretty serious one. Strange that nobody bothered to fix this properly yet from l2j team.

[Maneco2]

Issue #345 was marked as a duplicate of this issue.