  A massive gravity theory was proposed by Visser in the late nineties. This
theory, based on a backgroung metric $b_{\alpha \beta}$ and on an usual
dynamical metric $g_{\alpha \beta}$ has the advantage of being free of ghosts
as well as discontinuities present in other massive theories proposed in the
past. In the present investigation, the equations of Visser's theory are
revisited with a particular care on the related conservation laws.\ It will be
shown that a multiplicative factor is missing in the graviton tensor originally
derived by Visser, which has no incidence on the weak field approach but
becomes important in the strong field regime when, for instance, cosmological
applications are considered. In this case, contrary to some previous claims
found in the literature, we conclude that a non-static background metric is
required in order to obtain a solution able to mimic the $\Lambda$CDM
cosmology.
