When I was trying to build the FormEditor example (upp-win-13618 + MSVS19 Debug), I got:
upp\uppsrc\Core\Vcont.h (132): error C2280: "Upp::Vector<Upp::String>::Vector(const Upp::Vector<Upp::String> &)": attempting to reference a deleted function
It seems to me that Vector has a user-defined move ctor, which makes the compiler delete the default copy ctor and results in the error.