I really don't know much about this movie anymore, since I've seen it only once as a child more than 30 years ago in the early 80's.
It was black-and-white, probably from the 50's or 60's and although I was really fascinated and considered it as one of the best movies ever made it was probably a B-Movie of some kind.
Fragments of the story: Aliens are visiting Earth, whether for invasion or a friendly visit I can't remember. People are frightened and try to fight the aliens. Near the end, the Aliens are shown as large vaguely cone-shaped creatures of about 3 meters in height: one large cone with the tip at the bottom and one smaller cone or a dome at the top/head. The aliens moved by hovering over the ground.
Me and my siblings watched a lot of sci-fi movies like this during one year (in fact, every time grandma was babysitting). The movie was probably part of a series of the respective German TV station (WDR?) and might have something in common with the movie The Incredible Shrinking Man which I remember clearly from such an occasion.
Viewed It Came From Outer Space on Prime. Really enjoyed it and realised how much Jack Arnold shaped my sci-fi preferences but it is really not the film I am looking for.