Ошибка jass!

library Equipment initializer init

globals
   private integer array EQUIPMENTS
   private integer EQUIPMENT_ID = 'A000'
endglobals

struct Equipment
    private integer id = 0
    private integer level = 1
    
    static method addItem takes integer id returns thistype
        local thistype this = 0 
        set this = .allocate()
        set .id = id
        return this
    endmethod
endstruct

private function init takes nothing returns nothing
    local Equipment EquipmentItem = 0
    
    set EquipmentItem = Equipment.addItem('I000')
    set EquipmentItem.level = 5 // Тут ошибка почему? когда убираю то работает!
endfunction

endlibrary