Players inventory is messing up?!

My servers inventory pickup has recently been screwing up everyone’s inventories and items they had every restart it gives this error:
[ERROR] addons/itemstore/lua/itemstore/items/spawned_shipment.lua:7: attempt to index a nil value

  1. GetDescription - addons/itemstore/lua/itemstore/items/spawned_shipment.lua:7
  2. unknown - addons/itemstore/lua/itemstore/vgui/item.lua:20
    3. InvalidateLayout - [C]:-1
    4. unknown - lua/vgui/dlabel.lua:109
    does anyone know what i can do?

Code?

function ITEM:GetDescription()
return string.format( self.Description, CustomShipments[ self:GetData( “Contents” ) ].name, self:GetData( “Amount” ) )
end

I assume you purchased this script: https://scriptfodder.net/scripts/view/15 so contact the author of the script for help. Facepunch cannot help you with a paid script.