When trying to add an item or a set to a collection, I'm getting the following error and the collection list stays empty.

Lua Error:

3x ...aceBetterWardrobe/Modules/CollectionList.lua:142: attempt to call field 'GetSetSources' (a nil value) [string "@BetterWardrobe/Modules/CollectionList.lua"]:142: in function UpdateList'
[string "@BetterWardrobe/Modules/Wardrobe.lua"]:6138: in function func' [string "@BetterWardrobe/Libs/UIDropDownMenu/UIDropDownMenu.lua"]:905: in function BW_UIDropDownMenuButton_OnClick'
[string "*UIDropDownMenuTemplates.xml:139_OnClick"]:1: in function <[string "*UIDropDownMenuTemplates.xml:139_OnClick"]:1>

Locals:
self =

{
UpdateList = defined @BetterWardrobe/Modules/CollectionList.lua:118
SelectedCollectionList = defined @BetterWardrobe/Modules/CollectionList.lua:522
GenerateSourceListView = defined @BetterWardrobe/Modules/Sources.lua:459
BuildCollectionList = defined @BetterWardrobe/Modules/CollectionList.lua:23
AddMogItData = defined @BetterWardrobe/Modules/CollectionList.lua:420
AddList = defined @BetterWardrobe/Modules/CollectionList.lua:428
GenerateListView = defined @BetterWardrobe/Modules/CollectionList.lua:573
CurrentList = defined @BetterWardrobe/Modules/CollectionList.lua:511
IsInList = defined @BetterWardrobe/Modules/CollectionList.lua:467
TSMGroupExport = defined @BetterWardrobe/Modules/CollectionList.lua:668
Dropdown_Initialize = defined @BetterWardrobe/Modules/CollectionList.lua:311
CreateDropdown = defined @BetterWardrobe/Modules/CollectionList.lua:341
ListCount = defined @BetterWardrobe/Modules/CollectionList.lua:496
DeleteList = defined @BetterWardrobe/Modules/CollectionList.lua:453
Dropdown_OnClick = defined @BetterWardrobe/Modules/CollectionList.lua:303
BuildShoppingList = defined @BetterWardrobe/Modules/CollectionList.lua:101
RenameList = defined @BetterWardrobe/Modules/CollectionList.lua:442
showAll = true
OptionButton_OnClick = defined @BetterWardrobe/Modules/CollectionList.lua:370
}
type = "set"
typeID = 483
add = true
sourceID = nil
addSet = false
setName = nil
setInfo = nil
itemModID = nil
selectedList = 1
collectionList = {
set = {
}
item = {
}
name = "CollectionList"
extraset = {
}
}
sources = nil
(*temporary) = nil
(*temporary) = 483
(*temporary) = "attempt to call field 'GetSetSources' (a nil value)"
CollectionList = {
UpdateList = defined @BetterWardrobe/Modules/CollectionList.lua:118
SelectedCollectionList = defined @BetterWardrobe/Modules/CollectionList.lua:522
GenerateSourceListView = defined @BetterWardrobe/Modules/Sources.lua:459
BuildCollectionList = defined @BetterWardrobe/Modules/CollectionList.lua:23
AddMogItData = defined @BetterWardrobe/Modules/CollectionList.lua:420
AddList = defined @BetterWardrobe/Modules/CollectionList.lua:428
GenerateListView = defined @BetterWardrobe/Modules/CollectionList.lua:573
CurrentList = defined @BetterWardrobe/Modules/CollectionList.lua:511
IsInList = defined @BetterWardrobe/Modules/CollectionList.lua:467
TSMGroupExport = defined @BetterWardrobe/Modules/CollectionList.lua:668
Dropdown_Initialize = defined @BetterWardrobe/Modules/CollectionList.lua:311
CreateDropdown = defined @BetterWardrobe/Modules/CollectionList.lua:341
ListCount = defined @BetterWardrobe/Modules/CollectionList.lua:496
DeleteList = defined @BetterWardrobe/Modules/CollectionList.lua:453
Dropdown_OnClick = defined @BetterWardrobe/Modules/CollectionList.lua:303
BuildShoppingList = defined @BetterWardrobe/Modules/CollectionList.lua:101
RenameList = defined @BetterWardrobe/Modules/CollectionList.lua:442
showAll = true
OptionButton_OnClick = defined @BetterWardrobe/Modules/CollectionList.lua:370
}
addon = {
`

Should be fixed in the next update

I ran into the same error