it toke me some time but i fix it ...
1. U need open CUbase ....
2. open Project / or New
3. Press F11 to the Vst devices --- and open the virus VST
4. stay in th F11 Panel ... Next to the word " virus ti" you have a little arrow ... press on it
5. you need to disable the first --- "virus ti1 stereo" and enable "virus ti2 stereo"
6.Now go back to the Virus VST .... and go to the "Common" section
7. change the "main out" from "USB1 L+R" to "USB2 L+R" (you can go to the "patch utility" "usb audio mode" and chose "3 output /1 input" and the "USB3 L+R" will apper
in the common section "main out" and then the "virus ti3 stereo" will work (F11 panel)
8. Problem Solved !!!!!!
Enjoy Virus Ti ... 