How many movies have Erich Engel and Karl Haacker collaborated on?

They have worked on 3 movies together! Their first movie together was Gefährliches Spiel (1937) while their highest rated movie together was Unser Fräulein Doktor (1940). They have not worked together since Unser Fräulein Doktor (1940). They are most known for their drama films together.