Jane Austen's novel Pride and Prejudice is actually a good example of the general point that " Tragedy is not the only genre in which characters reveal a tragic flaw." Although the ending of the book is happy, much of the unhappiness experienced by the characters is caused by their own faults of character.
Mr. Darcy is excessively proud and prejudiced against those not as well bred as himself.
Elizabeth is too proud of her own wit and judges people too quickly.
Jane is too easily influenced by others.
Lydia, Kitty, and Mrs. Bennett lack judgement.
Mr. Bennett has good sense, but always follows the path of least resistance.