[en] In order to achieve peak luminosity of a Muon Collider (MC) in the 10³⁵ cm^-2s^-1 range very small values of beta-function at the interaction point (IP) are necessary (β* (le) 1 cm) while the distance from IP to the first quadrupole can not be made shorter than ∼6 m as dictated by the necessity of detector protection from backgrounds. In the result the beta-function at the final focus quadrupoles can reach 100 km making beam dynamics very sensitive to all kind of errors. In the present report we consider the effects on momentum acceptance and dynamic aperture of multipole field errors in the body of IR dipoles as well as of fringe-fields in both dipoles and quadrupoles in the ase of 1.5 TeV (c.o.m.) MC. Analysis shows these effects to be strong but correctable with dedicated multipole correctors.