sudenly my cubase 6.5 don't recognize my Focusrite preamp

Hi dear people
I’ve been using Cubase 6.5 and a Focusrite ISA ONE preamp’ in my home studio, for 2 years now…suddenly,when i try to go to -“Device Setup”"-Control Panel"- and switch from “Internal” to “spdif”… the “Control Panel” is not responding …!!!

Can you help me with this issue ?

Thank You

Arie