What problems did Germany face after World War I?

Germany faced numerous problems after World War I.  The most pressing involved the political climate.  After the defeat of Germany, the Wilhelm II was forced to abdicate and the Weimar Republic was declared.  This was only after a revolution that took place in 1918-19.  The Republic, however, was on shaky ground to begin with.  There were over thirty political parties, though only six had any real power.  This situation meant that parties had to form coalitions with one another to get anything done.  Since the parties were more interested in their survival than that of the makeshift Republic, these coalitions often proved weak.

There were also at least three major money problems.  First, the reparation payments of the Versailles Treaty, though still quite exorbitant, were manageable.  Second, the shift to a peace time economy was rather smooth because Germany continued to print money, which led to the astronomical inflation of 1923-4.  Third, because of the weakening by inflation and the dependence on foreign loans, the Great Depression hit Germany especially hard. 

What was most pressing, however, was the psychological shock of losing the war.  Many people, especially due to fabricated military reports, were surprised to learn of Germany's defeat.  (Hitler was one of these people.)  There was also the stab-in-the-back theory, insisting the military lost because of poor political support.