BERLIN — Preparing to face the voters again in 2017, Chancellor Angela Merkel has had to deal with an onslaught of challenges over the past year, from the Greek debt crisis to an upsurge in far-right populism to a rebellion in her own Christian Democratic Party over her open-door policy for Syrian refugees.But it’s unlikely that Ms. Merkel was expecting a problem on another front, a problem that could damage not only her electoral prospects but Germany’s global image as a model of economic quality, financial conservatism and market efficiency: the soundness and future of the country’s flagship financial institution, Deutsche Bank.
