ONCE AGAIN ABOUT THE PROBLEM “4/3”

It is shown that the problem "4/3" or the problem of electromagnetic mass has a strict solution only if the fields are instantaneous. This result is valid in both the classical and relativistic variants. The hypothesis of the existence of a physical ether is introduced, which allows us to explain the constancy of the speed of light in inertial reference systems and features of instantaneous action at a distance.