Thread:NoWayThisUsernameIsAlreadyOwnedBySomeone/@comment-26561761-20160326050417/@comment-26143371-20160526103027

OK that looks like a Wikia-bug. The first line says it cannot call the "importWikiaScriptPages" function because it does not (yet) exist. The call is made at the every end of the page through This causes the tabber-script not to be loaded in the first place. Subsequently it cannot run, cannot register itself to window.onlooad (hence the error in the third line) and cannot create the tabs when the page has loaded.

This is something which is best reported to [[Special:Contact/bug]. Since you're the one who encounters is regularly, it should be you who reports it.