I have Cubase 7.5 ,and a Yamaha EX5 with Usb2Midi Connection which is not recognized by Cubase…i don’t know why and i am sad about that, without keyboard,i can’t do very much with Cubase… , what should i do for Cubase to see my cable ? 
please…
One suggestion…
If running your Cubase on a Windows PC make sure to have your USB cable plugged in before starting Cubase.
Regards. 