At Quiz summary page, the retake button is not available anymore after review answers

Captivate is designed to work this way.  If users could simply fail a quiz, review the quiz to see all the correct answers, and then immediately click a button to retake the quiz, that would be facilitating cheating.

So, the Captivate design team opted NOT to make it possible to display the Retake Quiz button if the user has just Reviewed the Quiz.  The user must relaunch the entire module in order to make another attempt on the quiz.