What puzzle? Is it for a main plot quest or a side quest that you can skip?
Keara's statue names (the only puzzle I can think of off-hand that you could spend hours trying multiple combinations for)
Did you try emailing support@larian.com? They are on vacation now until the end of the month, unfortunately, but if a puzzle isn't working and you didn't just miss something, you may have run into a bug or glitch.
