Getting the following error every time when placing an order:

2x ...ns/ProfessionShoppingList/ProfessionShoppingList.lua:3603: attempt to compare number with nil
[string "@ProfessionShoppingList/ProfessionShoppingList.lua"]:3603: in function <...ns/ProfessionShoppingList/ProfessionShoppingList.lua:2512>

Locals:
self = Frame {
0 =
}
event = "CRAFTINGORDERS_ORDER_PLACEMENT_RESPONSE"
arg1 = 0
arg2 = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to compare number with nil"
app =

{
TrackingWindows = defined @ProfessionShoppingList/ProfessionShoppingList.lua:131
UpdateAssets = defined @ProfessionShoppingList/ProfessionShoppingList.lua:1214
nyiRecipes = {
}
SaveWindowPosition = defined @ProfessionShoppingList/ProfessionShoppingList.lua:115
Toggle = defined @ProfessionShoppingList/ProfessionShoppingList.lua:506
CreateAssets = defined @ProfessionShoppingList/ProfessionShoppingList.lua:624
UpdateNumbers = defined @ProfessionShoppingList/ProfessionShoppingList.lua:353
TooltipInfo = defined @ProfessionShoppingList/ProfessionShoppingList.lua:1304
Clear = defined @ProfessionShoppingList/ProfessionShoppingList.lua:1366
Settings = defined @ProfessionShoppingList/ProfessionShoppingList.lua:1390
Show = defined @ProfessionShoppingList/ProfessionShoppingList.lua:480
UntrackRecipe = defined @ProfessionShoppingList/ProfessionShoppingList.lua:596
TrackRecipe = defined @ProfessionShoppingList/ProfessionShoppingList.lua:517
Initialise = defined @ProfessionShoppingList/ProfessionShoppingList.lua:46
iconReady = "Interface\RaidFrame\ReadyCheck-Ready"
OpenSettings = defined @ProfessionShoppingList/ProfessionShoppingList.lua:1385
GetReagents = defined @ProfessionShoppingList/ProfessionShoppingList.lua:292
dump = defined @ProfessionShoppingList/ProfessionShoppingList.lua:27
slLegendaryRecipeIDs = {
}
UpdateRecipes = defined @ProfessionShoppingList/ProfessionShoppingList.lua:432
WindowFunctions = defined @ProfessionShoppingList/ProfessionShoppingList.lua:2004
iconWaiting = "Interface\RaidFrame\ReadyCheck-Waiting"
iconNotReady = "Interface\RaidFrame\ReadyCheck-NotReady"
Print = defined @ProfessionShoppingList/ProfessionShoppingList.lua:41
}