Hi,
Are you using sx3 or sx1?
Did you select the proper BUS (in sx3) for mixdown?
In sx1 you can choose to do mixdown with or without effects.

sx3

Check the following things

did you bypass the effects or are they muted? (sometimes if you solo something not connected to those fx this occurs)

are the fx routed to your stereo output bus - look at the fx channel strip and make sure it is routed to your main stereo outs and not some other virutal outs or disconnected.

if you still have no joy log into cubase.net and post on the forum, you will probably get numerous answers within a few hours

okay thanks everyone !!! how do you select the bus?

the easiest way is to either do it on the channel strip, or right mouse click on the effect, or use the device panel setup.

thanks !!

If You'll go to the Cubase fourm and enter your Dongle number you'll find all the help you'll ever need for SX.
Larry

By the way your answers are in the Cubase manual.