What were the most important weaknesses of the Weimar Constitution?

In my opinion there are two major weaknesses in the Weimar Constitution - firstly, the context for its creation and, secondly, the P.R. voting system... The Weimar constitution was created by Wilhelm the Second. He created the constitution and the democratic government as an alibi; he saw the impeding defeat and decided on trying to create a scapegoat that could take the blame for the war and everything that went with it. For the …

…final weakness that I feel is worth discussing is the fact that the Reichstag have no control whatsoever over the army so have no real power (survival of the fittest). The fact is that even though the President is meant to be controlling the army it is almost a role reversal: the army leaders can to an extent dictate what the President does because they are the President's backup, a safety net if you will.