Hi,
I have a sketch, padded up to a solid, that I want to mirror horizontal and vertical with the mirror feature of the PartDesign workbench. The first mirroring works like expected, but for the second one I get the error message "Bitte zuerst eine subtraktive oder additive Funktion erstellen", in English something like: "Create a subtractive or additive function first". But how do I do this? The Part Union tool does not work for single objects.