Warrior
Commanding Presence does not work.
Improved Slam does not work, even on rank 2, casting time still remains 1.5 sec
Improved Whirlwind does not cool down
Retalliation ability is not working. It does only 1 damage to per enemy, instead of weapon damage per hit.
Improved Thunderclap: no extra slow, no extra damage

Skills
Charge: does not generate any Rage
Rend: does not produce damage depending from weapon, only the first damage
Retaliation: does not produce any damage
Stance Mastery: does not work

Arms Talents
Improved Rend: does not work
Improved Charge: does not work
Iron Will: does not work (I think lacks the procedure to resist Stun, Roots etc...)
Deep Wounds: does not work
Two Handed Weapon Specialization: does not work
Mace Specialization: does not work
Sweeping Strike: does not work
Weapon Mastery: does not work
Improved Harmstring: does not work
Blood Frenzy: does not work
Second Wind: does not work (maybe it generates rage but i'm not sure of that)
Improved Mortal Strike: does not work
Endless Rage: does not work
Sword specialisation trigger the effect but dont do another hit. (similar to windfury bug)

Fury Talents
Booming Voice: does not work
Commanding Presence: does not work
Dual Wield Specialization: does not work

Protection TalentsOne Handed Weapon Specialization: does not work

Rogue

NE rogues can stay in shadowmeld while moving (go in shadowmeld, go stealth, unstealth, and then u can move with shadowmeld, and normal speed)
When rogues go stealth, they gain 2x attack power, but when they unstealth, it doesnt go back to normal

Druid
After gaining lvl 255, when you open your character screen, your game will crash (error #132
Shapeshift form
When going in Dire bear form you get 42243 armors (with 1877 armors equiped)
Fly form dont receive any movement speed bonus.
Cat form ap bonus dont seem to scale to lvl 60 like its supposed to be.
Bear form ap bonus dont seem to scale to lvl 60 like its supposed to be.
When shifting to a form and going back to humanoid, there a chance you wont have any mana bar or your mana bar will be bugged and its will tell no mana. Relog if its happen.

Restoration talents
Nature swiftness dont work
Tree form dont work and or dont show model
Balance Talents
Force of nature dont work

Feral Talents and skills
Hearth of the wild give to caster the intelligence, to bear the stamina, but he dont give to cat form the 20% strength.
Leader of the pack and improved leader of the pack dont work.
Mangle dont give a combo point.
Swipe can turn your attack off
Primal fury dont work.
Maim break on his own bleed over time, this skill should not break on bleed damages over times.

Shaman Char test : dranei shaman lvl 145
Elemental talents
clearcasting seem to always pop on any spell but dont reduce the mana cost
Eye of the storm proc but has no effect

Enhancement talents
Unleashed rage proc, but dont seem to affect attack powers.
Stormstike work, the debuff work, but sometime its do 2 attack at the place of 1.

Weapon buff
windfury dont proc another attack and I cant tell if its add the supposed +ap
cant apply rockbiter on weapons
Flametong dont work

Totem
Totem of wrath dont work
all the supposed effects of weapon buff that dont work dont work when its the totem that apply it.
All the totems lvl 61-70 dont work

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General
Defense skill seem to take alot of time to increase.
Crit/spell crit/spell dmg/hitting/dodge rates on items do not work, or, at least, do not show in the char panel. (Mangos and confirmed)
Mangos speed system is bugged, Its will make you stop moving (see druid marshald set bonus bug)
Talents that reduce the casting time or increase the spell ranges do not work. (Mangos)
Spirit healers at easterplagueland for the south west part is not located at the good place or the death place is not the good one.
All talents that reduce rage or energy cost dont work.
Majority of the quests in outlands dont work and give about 100g each without doing anything.
All the instant skills with melee damage (as well as Mortal Strike, Slam, Harmstring etc) have less than 5yd range.
Melee spells as Heroic Strike should not consume Rage if missed/parried/dodged. ( I think its supposed it but ...? )
Flight mount can fly underwater.

Gear
Druid marshald set bonus that increase shapeshift form speed by 15% make your character stop moving. Also the set work on humanoid form and shouldnt not.
Putting a gem in your socket result in an instant dead.

Race specific
Dranei Racial dont scale and bonus to you and group dont work.
Night elf : wisp spirit dont work.

I first would like to thank Kity for putting this together. Me and the other Moderators should possibly take this in to a compiled list and update accordingly.

Would you like to put the topic as a stiky, tried to buy one from the plaza but didnt finded how its worked.

Also I try to check at mangos forum so the bugs that will be patched in the next revision wont be in the topic.

If you find any bug plz post it on this post by respecting the structure in the first post

updated

updated :P

kp do you have an anti-speedhack on your server? I think its why the feral set bonus is bugged.

speeds are bugged in mangos from what I hear, overspeed etc is an issue in Battlegrounds too.

what i have seen is if I cant move with the set bonus, I shift in and out of catform and its ok.

1.talents that reduce the casting time or increase the spell ranges do not work.
2.Crit/spell crit/spell dmg/hitting/dodge rates on items do not work, or, at least, do not show in the char panel.

thats from mangos buglist.