Cubase 8.5 and Yamaha Motif Xs VST Editor

Hi I am trying to set up a workable set up between Cubase 8.5 on macbook pro and Yamaha Motif XS VST Editor and they aren’t talking at all. I can’t get the DAW and XS to connect I have Firewire . They used to with my Cubase 4. What am I doing wrong ?