Djm s9 failed to connect audio with Serato

Hello , i hope somebody can help me becuse i am struggling sevearl days about thsi issue:

i have mac book pro with hight sierra 10.13.2

my djm s9 , when connects in Serato , gives me an error " failed to connect audio"

i checked in audio output of preferences , and there is no Djm s9 in the list

the midi studio shows the djms9 and the check in out works correctly .

all , firmware and  drivers are updated .

i don't know what to do anymore

HEEEELP

thanks

Carlo