From the just-released 82nd Annual Report [PDF] of the Bank of International Settlements:
The world is now five years on from the outbreak of the financial crisis, yet the global economy is still unbalanced and seemingly becoming more so as interacting weaknesses continue to amplify each other. The goals of balanced growth, balanced economic policies and a safe financial system still elude us. In advanced economies at the centre of the financial crisis, high debt loads continue to drag down recovery; monetary and fiscal policies still lack a comprehensive solution to short-term needs and long-term dangers; and despite the international progress on regulation, the condition of the financial sector still poses a threat to stability. From time to time, encouraging signs raise hopes – but they are quickly dashed, delivering another blow to the confidence of consumers and investors.
And from the report, the crisis explained in graphic form [click on the image to enlarge]: