  The tidal disruption of old, compact stellar structures provides strong
constraints on macroscopic dark matter candidates such as primordial black
holes. In view of recent, new observational data on the Eridanus II dwarf
galaxy and on its central stellar cluster, we employ, for the first time,
$N$-body simulations to assess the impact of compact massive dark matter
candidates on the gravitational stability of the cluster. We find evidence that
such candidates must be lighter than about one solar mass if they constitute
the totality of the dark matter. We additionally derive robust constraints on
the fraction of the dark matter in macroscopic objects as a function of mass,
by suitably modeling the remainder of the dark matter as standard fluid-like
cold dark matter.
