 This potential for non-existence of equilibrium (which was formally developed in Hart’s counterexamples to existence of equilibrium) left the literature in limbo for almost a decade, until Cass’s work on existence in economies with purely financial assets pointed the way out.As Geanakoplos notes

The first paper that Geanakoplos references above appeared initially in April 1984 as a CARESS Working Paper.This work was followed very quickly by results showing that the non-existence problem pointed out by Hart was not generic, and led ultimately to the generic existence results of Duffie and Shafer, and again spawned a new literature looking positively at the welfare implication of market incompleteness, and normatively at issues of asset engineering.