FWIW: I've managed to produce a few of these too - generally arose after futzing with a failed dependency, reaching for the "nuke it" ( 'completely remove' tool) button, then reinstalling it - sometimes there's a complaint that the same version was previously installed (even though it had been supposedly totally nuked), sometimes not - but occasionally a white 'new' ghost will reappear in the manage installed tools list after reinstallation - AFAIK those white ghosts are impossible to remove...