Vittoria Vici's Wedding is horribly bugged

Question

I'm doing the quest Bound Until Death and there are some pretty serious bugs surrounding the wedding.

If you go to the wedding, there is nobody there, the Jarl is there and one other girl standing by the gate singing. Half the time Vittoria Vici isn't even there and her groom is never there.

If Vittoria Vici is standing on the balcony, the quest marker isn't pointing at her, it points at the door that leads to her and when you go through that door, the quest marker switches to her. However, you can't kill her, she must still be considered essential for some reason, it's like the quest has started in some ways, but not in other ways.

Here's a picture of me being unable to kill her:

All the guests are bugged too. If you go to the inn, they're all just standing around doing nothing. It's like they know they should have something to do besides their normal schedules, but they haven't been told by the game what it is they should be doing. However, if you talk to them, they think they're at the wedding and have all the normal dialogue options for if they were there.

Here's them standing around doing nothing, there's a lot of them:

I am playing on PC with a number of mods, so here is my load order:

GameMode=Skyrim
Skyrim.esm=1
Update.esm=1
Unofficial Skyrim Patch.esp=1
Dawnguard.esm=1
Unofficial Dawnguard Patch.esp=1
HearthFires.esm=1
Unofficial Hearthfire Patch.esp=1
Dragonborn.esm=1
Unofficial Dragonborn Patch.esp=1
Skyrim Project Optimization - Full Version.esm=1
Falskaar.esm=1
Wyrmstooth.esp=1
ApachiiHair.esm=1
SPERG.esm=1
moonpath.esm=1
HighResTexturePack01.esp=1
HighResTexturePack02.esp=1
HighResTexturePack03.esp=1
3DNPC.esp=1
KKSDrBWeightFix.esp=0
ABT - Faster Bolts Improved +50%.esp=1
BetterQuestObjectives.esp=1
barenziahquestmarkers.esp=1
ABT - Bolts Renamed for BS and CCO.esp=0
AMB Glass Variants Lore.esp=1
FullBootForKKSA.esp=0
Better Dynamic Snow.esp=1
CalienteVanillaArmorTweaks.esp=0
Duel - Combat Realism.esp=1
blaze of eventide.esp=1
BetterQuestObjectives-Dawnguard.esp=1
SPERG-DB.esp=1
RealisticWaterTwo - Waves - Falskaar.esp=1
RealisticWaterTwo.esp=1
BetterQuestObjectives-DBForevertoMisc.esp=1
DeadlyDragons.esp=1
DeadlyDragonsArmory.esp=1
DeadlyMonsters.esp=1
DHuntress.esp=1
RaceMenu.esp=1
Differently Ebony.esp=1
SPERG-DG.esp=1
BetterQuestObjectives-Hearthfire.esp=1
Book Covers Skyrim.esp=1
ABT - Faster Arrows Improved +50%.esp=1
ethereal_elven_overhaul.esp=1
ESPv1_1.esp=1
SPERG.esp=1
FlameAtronachArmor.esp=1
Chesko_WearableLantern.esp=1
RealisticWaterTwo - Wyrmstooth.esp=1
SplashofRain.esp=1
Helgen Reborn.esp=1
betterinns.esp=1
Hothtrooper44_Armor_Ecksstra.esp=1
Footprints.esp=1
Footprints - Ash.esp=1
iHUD.esp=1
Immersive Sounds - Compendium.esp=1
dD - Enhanced Blood Main.esp=1
dD-Dragonborn-Dawnguard-EBT Patch.esp=1
ISCompendium Enhanced Blood Patch.esp=1
KKFur.esp=1
KKSDGWeightSliderFix.esp=0
WetandCold.esp=1
Locational Damage.esp=1
merchant gold increase.esp=1
RaceMenuPlugin.esp=1
Realistic crime report radius.esp=1
RealisticWaterTwo - Falskaar.esp=1
unreadbooksglow.esp=1
SkyUI.esp=1
AchieveThat.esp=1
DVA - Dynamic Vampire Appearance.esp=1
Customizable Camera.esp=1
LessIntrusiveHUD.esp=1
Undeath.esp=1
SkyTEST-RealisticAnimals&Predators.esp=1
BetterDarkBrotherhood.esp=1
ElderOutfit.esp=1
Guard Dialogue Overhaul.esp=1
Immersive Weapons.esp=1
ABT - Progressive Damage (Vanilla).esp=0
Better Vampires.esp=1
Cloaks - Dawnguard.esp=1
RiverWood Redux.esp=1
skyBirds - Airborne Perching Birds.esp=1
BirdsHFclean.esp=1
Hothtrooper44_ArmorCompilation.esp=1
aMidianborn_Skyforge_Weapons.esp=1
BetterQuestObjectives-AMBSkyforgePatch.esp=1
SPERG Immersive Armors.esp=1
bettermorthal.esp=1
BellyachesNewDragonSpecies.esp=1
RealisticWaterTwo - Legendary.esp=1
RealisticNeedsandDiseases.esp=1
Radiant and Unique Potions Poisons and BOOZE.esp=1
RND_Dawnguard-Patch.esp=1
RND_Dragonborn-Patch.esp=1
RND_USKP-Patch.esp=1
run for your lives.esp=1
Cloaks.esp=1
quest_thebiggertheyare.esp=1
1nivWICCloaks.esp=1
1nivWICSkyCloaksPatch.esp=1
SMIM-Merged-All.esp=1
quest_nomercy.esp=1
Immersive Patrols II.esp=1
moonpath_questdata.esp=1
quest_seaofghosts.esp=1
markarth_plus.esp=1
flaho_shi_eagles_nest_eng.esp=1
betterdawnstar.esp=1
bettermarkarthexterieur.esp=1
Inigo.esp=1
Skyrim Flora Overhaul.esp=1
Chesko_Frostfall.esp=1
RND_HearthFires-Patch.esp=1
RealisticWaterTwo - Waves - Wyrmstooth.esp=1
quest_sorcery.esp=1
RND_AnimalLoot.esp=1
SFO - Dragonborn.esp=1
tavevillages.esp=1
quest_andtherealmsofdaedra.esp=1
when vampires attack.esp=1
WetandCold - Ashes.esp=1
whiteruninenhanced.esp=1
betterwinterhold.esp=1
riverwoodenhancedplugin.esp=1
whiterunexenhanced.esp=1
DragonCombatOverhaulDragonborn.esp=1
hallsofdovahndor.esp=1
The Paarthurnax Dilemma.esp=1
BetterQuestObjectives-PaarDilemmaPatch.esp=1
tavewindhelm.esp=1
tavesolitude.esp=1
The Dance of Death - Ultimate Edition.esp=1
taveriften.esp=1
dragonpriestmaskquestmarkers.esp=1
Hunterborn.esp=1
Hunterborn_Frostfall-Patch.esp=0
Hunterborn_Dawnguard-Patch.esp=1
Hunterborn_RND-Patch.esp=1
tavefalkreath.esp=1
Vampire Skin Color Fix.esp=1
Brevi_MoonlightTales.esp=1
BetterQuestObjectives-MoonlightPatch.esp=1
Riverwood Redux Expanded Basement.esp=1
ForgottenMagic_Redone.esp=1
Alternate Start - Live Another Life.esp=1
BetterQuestObjectives-AlternateStartPatch.esp=1
Bashed Patch, 0.esp=1

What type of conflict could possibly cause something like this? Is this a normal bug? Because it isn't listed on any of the wiki's so I'm thinking it has to be a mod that caused it.

Also, I can't find any evidence of anybody having a similar problem anywhere.

Edit 1: Found the husband, he's standing in the inn doing nothing with everyone else.

Edit 2: I could probably fix this by using the console to mark Vittoria as non-essential so I can kill her, but I'd really rather fix this so I can enjoy the quest as intended.

Update: Well, disabling Dark Brotherhood Resurrection did not solve the issue. Also, I found out it's not just Vittoria that can't be killed. It's everybody! I can't kill anyone in Solitude! Everyone outside Solitude seems to be acting normal except for one guy on the road right outside who's just kneeling down with his arms over his head like he's scared and interacting with him doesn't do anything.

Update 2: I think might be a bug relating to sleeping in an inn. This post outlines a problem he had where he can't kill anyone, similar to mine, but I think mine is probably worse because it happened during a special event.

Answer 1

That quest is very bugged, yes. Try using http://www.uesp.net/wiki/Skyrim:Console#resetquest to reset the quest completely. Then when you go do it keep the following in mind

1. Go right to the wedding area as soon as you start the quest without faffing about
2. Kill her by dropping the statue on her, everything else is really bugged.
3. You ABSOLUTELY MUST go by (while visible and not sneaking) the entrance to the courtyard (near the door that leads to the balcony) to cause everyone to become hostile to you and that argonian assassin to spawn there and tell you that he will "hold them off" and only then should you run out of the city. If you actually escape unseen the city will become broken.
4. After finishing this quest, don't start the next one until you finish the thieves guild. Because the dark brotherhood is going to put an unavoidable 1500g bounty on you in solitude later on and you could really use that "pay 50% to erase the crime" ability they grant (although if you really wanted to, you could just console away your crime instead... or serve time)

Answer 2

So you were the only one who had this problem right? Well, the usep knows it too:

Sometimes after the Bound Until Death quest is activated, there will be a rare chance that the wedding area is completly empty. The guests that are supposed to be at the wedding are either walking around Solitude or not there at all. Vittoria will still have her essential flag if the player attempts to kill her when she is walking around town and you will still get attacked by guards, aswell as getting the standard bounty for attacking a citizen. On the rare occation, the wedding area will not even have the decorations, yet Vittoria will be walking around Solitude in her wedding dress. Reloading from a previous save does not seem to work, and the cause/fix is unknown.

It seems that reloading a save doesn't work at all. Try using console commands on her saying setessential 0 to disable her essentialness. You also said that when you slept in a bed, it can mess up NPC's als. Try sleeping in a bed one or more times to see if it resets the NPC's al. Maybe one of your mods might have messed up. I see you have Better DB Forever and Better Dark Brotherhood. Try to redownload those or delete them to see if it works. If the problem still occurs, you can use cheats to activate the next stage to continue the quest. hope it works, otherwise, you're doomed!