For an economy with dysfunctional intertemporal financial markets the financial sector is modelled as a competitive banking sector offering deposit contracts. In a setting related to Allen and Gale (JoF, 1998) properties of the optimal liquidity provision are analyzed for illiquid assets with ambiguous returns.In the context of our model, ambiguity -- i.e. incalculable risk -- leads to dynamically inconsistent investor behaviour. If the financial sector fails to recognize the presence of ambiguity, unanticipated fundamental crises may occur, which are incorrectly blamed on investors 'loosing their nerves' and 'panicing'.The basic mechanism of the Financial Crisis resembles the liquidation of illiquid assets during a banking panic. The combi...