I created a model in MED, then I imported it to WED, build the map and started preview map. I wanted to see how the model looks like, but there was only a blue screen. Why can't I see anything ?

Hi!

Did you put a position (camera) in WED.
The camera should be pointed in the direction of your mdl.

Hope this helps

Ottawa

Without a camera position set, the camera faces at a default 0,0,0. Apparently, as you are seeing a blue screen you put nothing in sight of the camera.