It's not referencing BigWigs, it's referencing libraries. BW is higher alphabetically, so it's versions of the libraries (as long as they're the most recent in your addons folder) are what get loaded into WoW's memory.
Make sure you have the latest version of Wardrobe2 and your addons/libraries.
edit: seems that Wardrobe2 hasn't been updated in some time. If it is indeed a conflict with some libraries, then Wardrobe2 hasn't been updated to fit with changes made. If things aren't resolved in a timely fashion for you, there is ItemRack, Outfitter, and ClosetGnome.