Let me explain. After the success of his letters, Root was moved to publish Henry Root's World of Knowledge. Rafe Champion points out that many academic philosophers share his misunderstanding of Popper's philosophy.
POPPER, Sir Karl (b 1902); Member of the Vienna Circle. "That which is unfalsifiable is meaningless." Did he solve the problem of induction? The argument still rages. See Swans.As Champion says, Popper never saw falsifiability as a criterion of meaning. It was a way of differentiating what was science from what was not.
True scientific theories can be refuted by observation, whereas pseudo-scientific theories - Popper saw Marxism and Freudianism as the worst offenders - are compatible with any state of affairs and therefore explain nothing.
For more on Popper see this website or the excellent short book by Bryan Magee.