Final answer:
The major weaknesses of the Weimar Constitution included the inability to respond to crises and political deadlock. Two revolutions were attempted afterward.
Step-by-step explanation:
The major weaknesses of the Weimar Constitution included the inability to respond to crises and the constant political deadlock in the Reichstag due to the large number of political parties. These weaknesses hindered the effectiveness of the Weimar government. After the Weimar Republic, two revolutions were attempted in Germany.