Unsure why it happened now and not previously, first time I've seen it.

1x ...eBetterWardrobe/Modules/SortingFunctions.lua:252: bad argument #1 to 'sort' (table expected, got nil)
[string "=[C]"]: in function sort' [string "@BetterWardrobe/Modules/SortingFunctions.lua"]:252: in function <...eBetterWardrobe/Modules/SortingFunctions.lua:217> [string "@BetterWardrobe/Modules/SortingFunctions.lua"]:446: in function ?'
[string "@BetterWardrobe/Modules/SortingFunctions.lua"]:670: in function SortSet' [string "@BetterWardrobe/Modules/Wardrobe.lua"]:4415: in function SortSets'
[string "@BetterWardrobe/Modules/Wardrobe.lua"]:4544: in function GetBaseSets' [string "@BetterWardrobe/Modules/Wardrobe.lua"]:5063: in function <BetterWardrobe/Modules/Wardrobe.lua:5058> [string "=[C]"]: in function Show'
[string "@Blizzard_UIParentPanelManager/Mainline/UIParentPanelManager.lua"]:493: in function SetUIPanel' [string "@Blizzard_UIParentPanelManager/Mainline/UIParentPanelManager.lua"]:336: in function ShowUIPanel'
[string "@Blizzard_UIParentPanelManager/Mainline/UIParentPanelManager.lua"]:174: in function <...ParentPanelManager/Mainline/UIParentPanelManager.lua:169>
[string "=[C]"]: in function SetAttribute' [string "@Blizzard_UIParentPanelManager/Mainline/UIParentPanelManager.lua"]:888: in function ShowUIPanel'
[string "@Blizzard_UIPanels_Game/Shared/PlayerInteractionFrameManager.lua"]:205: in function <...Panels_Game/Shared/PlayerInteractionFrameManager.lua:187>
[string "=(tail call)"]: ?
[string "@Blizzard_UIPanels_Game/Shared/PlayerInteractionFrameManager.lua"]:240: in function <...Panels_Game/Shared/PlayerInteractionFrameManager.lua:237>
[string "=[C]"]: in function `TurnOrActionStop'
[string "TURNORACTION"]:4: in function <[string "TURNORACTION"]:1>

Locals:
(*temporary) = nil
(*temporary) = "table expected, got nil"