I narrowed it down to Arwen's Realism tweaks, for some reason with that I cna't tan gecko hides. Load order, if it helps:

FalloutNV.esm
HonestHearts.esm
OldWorldBlues.esm
LonesomeRoad.esm
Caliber.esm
CaliberXgunrunners.esm
CaliberXhonesthearts.esm
CFWNV.esm
More Perks.esm
More Traits.esm
More Perks for Honest Hearts.esm
More Perks for Old World Blues.esm
GunRunnersArsenal.esm
CaravanPack.esm
IWR.esm
FNVToolkit.esm
Arwen_NV_Core.esm
NSkies - Vanilla Edition.esm
NVInteriors_Core.esm
NVInteriors_Urban_Edition.esm
NVInteriors_Urban_Edition_AWOP.esm
AWorldOfPain(Preview).esm
Primary Needs HUD.esm
IWS-Core.esm
RH_IRONSIGHTS_NV.esm
Military NV Backpacks.esm
Stealing -1 Karma.esp
DarNifiedUINV.esp
CASM.esp
IWR - Rebuilt.esp
The Mod Configuration Menu.esp
NewStripMapMarkers.esp
NewVegasBounties.esp
NewVegasBountiesII.esp
More Perks Update.esp
More Perks for Honest Hearts Update.esp
More Perks for Old World Blues Update.esp
More Traits Update.esp
IWS-Core-Patrols.esp
IWS-Core-Guards.esp
IWS-Core-Civilians.esp
IWS-HH.esp
IWS-OWB.esp
IWS-LR.esp
pipboy2500_edisleado.esp
OverTheShoulder.esp
XP_Sound.esp
PortableCampsite.esp
Sprint Mod.esp
Improved Throwing1.esp
QS_Blackwolf_NV_Backpackmod.esp
FlashlightNVSE.esp
CFW-LR.esp
CFW-HH.esp
CFW-OWB.esp
CFW-GRA.esp
AWOPCaliberXAmmoPatch.esp
AWOPLowLootGeneral.esp
AWOPLowLootMWeapons.esp
AWOPLowLootSkillBooks.esp
Realistic_Repair_NV.esp
aaaJNFSniperZooming.esp
dD - Enhanced Blood Main NV.esp
dD-Reduced Ragdoll Force.esp
dD-Smaller Spatters Realistic.esp
removechal.esp
Dynamic Quantity Prompt.esp
Faster Terminals.esp
GrenadeHotkey.esp
WeaponModsixpanded.esp
WMX-AWOP.esp
WMX-AWOP-Overhaul.esp
WMX-Arwen_NV_Realism.esp
WMX-ModernWeapons.esp
WMX-HonestHearts.esp
WMX-OldWorldBlues.esp
WMX-LonesomeRoad.esp
WMX-MW-GRA.esp
WMX-GunRunnersArsenal.esp
WMX-PreOrderPackCaravan.esp
The Weapon Mod Menu.esp
RH_IronSights_NV_Vanilla.esp
Military NV Backpacks - Vendor Script Replenish.esp
RH_IronSights_NV_PreCaravan.esp
Military NV Backpacks - BumBagUseSlot1.esp
GoodspringsSewer-1.22.esp
Wasteland Defense.esp
Arwen_NV_Realism_Core.esp
Arwen_NV_Hard-Core.esp
Arwen_NV_Med-Tec.esp
Expensive3.esp
Total active plugins: 91
Total plugins: 94

You need to have a knife or combat knife in your inventory.

EDIT: Nevermind, you're right. Thanks man. Mods, you can close this.