error with boneattach

[Padul]

this showups in console

[2016-02-28 17:21:05] ERROR: [DayZ-MTA]/DayZ/survivorSystem.lua:395: attempt to call global 'attachElementToBone' (a nil value)  
[2016-02-28 17:20:54] ERROR: [DayZ-MTA]/DayZ/survivorSystem.lua:437: attempt to call global 'detachElementFromBone' (a nil value)  
[2016-02-28 17:20:48] ERROR: [DayZ-MTA]/DayZ/survivorSystem.lua:434: attempt to call global 'attachElementToBone' (a nil value)  
[2016-02-28 17:20:47] WARNING: [DayZ-MTA]/DayZ/survivorSystem.lua:343: Bad argument @ 'setPedSkin' [Expected element at argument 1, got number '179']  
[2016-02-28 17:20:47] ERROR: [DayZ-MTA]/DayZ/survivorSystem.lua:437: attempt to call global 'detachElementFromBone' (a nil value)  
[2016-02-28 17:20:14] ERROR: [DayZ-MTA]/DayZ/survivorSystem.lua:397: attempt to call global 'attachElementToBone' (a nil value)  

--attaches 
local elementBackpack = {} 
function backPackBack (dataName,oldValue) 
    if getElementType(source) == "player" and dataName =="MAX_Slots" then 
        local newValue = getElementData(source,dataName) 
        if elementBackpack[source] then 
            detachElementFromBone(elementBackpack[source]) 
            destroyElement(elementBackpack[source]) 
            elementBackpack[source] = false 
        end 
        local x,y,z = getElementPosition(source) 
        local rx,ry,rz = getElementRotation(source) 
        if newValue == 12 then 
            elementBackpack[source] = createObject(3026,x,y,z) 
        elseif newValue == 16 then 
            elementBackpack[source] = createObject(1248,x,y,z) 
        elseif newValue == 26 then 
            elementBackpack[source] = createObject(1575,x,y,z) 
        elseif newValue == 36 then 
            elementBackpack[source] = createObject(1252,x,y,z) 
        elseif newValue == 8 then 
            return 
        end 
        if newValue == 26 then 
            attachElementToBone(elementBackpack[source],source,3,0,-0.16,0.05,270,0,180) 
        else 
            attachElementToBone(elementBackpack[source],source,3,0,-0.225,0.05,90,0,0) 
        end 
    end  
end 
addEventHandler ( "onElementDataChange", getRootElement(), backPackBack ) 
  
function backpackRemoveQuit () 
        if elementBackpack[source] then 
            detachElementFromBone(elementBackpack[source]) 
            destroyElement(elementBackpack[source]) 
        end 
        if elementWeaponBack[source] then 
            detachElementFromBone(elementWeaponBack[source]) 
            destroyElement(elementWeaponBack[source])    
            elementWeaponBack[source] = false 
        end  
end 
addEventHandler ( "onPlayerQuit", getRootElement(), backpackRemoveQuit )) 

[Enargy,]

is bone_attach has been running?

[Padul]

ok, it wasnt running, thx for help