  The recent Dark Energy Survey Year 1 (DES-Y1) analysis of galaxy cluster
abundances and weak lensing produced $\Omega_{\rm m}$ and $\sigma_8$
constraints in 5.6$\sigma$ tension with Planck. It is suggested in that work
that this tension is driven by unmodelled systematics in optical cluster
selection. We present a novel simulation-based forward modeling framework that
explicitly incorporates cluster selection into its model predictions. Applying
this framework to the DES-Y1 data we find consistency with Planck, resolving
the tension found in the DES-Y1 analysis. An extension of this approach to the
final DES data set will produce robust constraints on $\Lambda$CDM parameters
and correspondingly strong tests of cosmological models.
