But it happens once in a while.
“As of the early 1200s, mentions of Greek Fire disappear from accounts of battles, for unknown reasons. It’s possible that the secret had been forgotten by the Byzantines themselves during the general decline of their state. Both the manufacture and the operation of Greek Fire was highly compartmentalized to ensure nobody could know the whole system, and it’s not a stretch to think that such a complex logistical effort couldn’t be maintained as the empire shrunk.”