I have managed to get a track together now I have moved on to the mixing stage but when I bring up a plug in and click preview there is no sound of the preview?. I have read about this elsewhere and people said I need to change the output on my computer rather than cubase but this hasn’t worked for me. Is there anything else to try? Thanks. Joey. 
Sorry, but what’s that preview you are clicking? And what plug-in? Decribe your situation in more detail.
If not using Control Room, make sure it’s dis-abled. If using it, set up a monitor bus in it.