What does this traffic sign combination indicate?

This traffic sign indicates the end of a traffic-calming zone (often called a "residential area" or "play street" in Germany). Within such zones, strict rules apply: pedestrians and children playing have priority, and vehicles must drive at very low speeds, usually walking pace. The sign with a red diagonal line crossing it means you are now leaving this special zone, and normal traffic rules apply again.

So, after this sign, drivers no longer need to prioritize pedestrians as strictly, and the speed limits and right-of-way rules return to standard road regulations. This explains why this sign combination marks the end of a traffic-calming zone, not a pedestrian zone or a children's playground area itself.