Whenever I open my appearances tab, or the collections, whether from within the UI or at a transmogrifier, I get this spam:

100x ...aceBlizzard_FrameXMLUtil/CollectionsUtil.lua:482: bad argument #1 to 'ipairs' (table expected, got number)
[C]: in function 'ipairs'
[Blizzard_FrameXMLUtil/CollectionsUtil.lua]:482: in function 'AreAllSourcesDisplayableOnPlayer'
[Blizzard_FrameXMLUtil/CollectionsUtil.lua]:493: in function 'GetAppearanceVisibilityWarning'
[Blizzard_FrameXMLUtil/CollectionsUtil.lua]:501: in function 'GetBestVisibilityWarning'
[BetterWardrobe/Modules/Wardrobe.lua]:3417: in function 'RefreshAppearanceTooltip'
[BetterWardrobe/Modules/Wardrobe.lua]:3407: in function 'SetAppearanceTooltip'
[BetterWardrobe/Modules/Wardrobe.lua]:3824: in function <BetterWardrobe/Modules/Wardrobe.lua:3798>

Locals:
(*temporary) = 57059
(*temporary) = "table expected, got number"

Fix already added to 'pull requests'. Looks like it'll be added in by the creator later if you can't make the edits yourself :)