Not moving in any gear

Have you checked the High-Low ratio lever.  Half-way between High and Low is a Neutral, so no drive to any axle even if a gear in the main box is selected.
Try locking the differential.  If this gives you drive, then it might be a final drive (half-shaft) failure.

Check that you have transmison fluid if not top off then post what you find. did it make a noise? or did it just doing it suddenly?

Hi my 300tdi auto discovery 98, will start up and idle when in park or neatrul,and rev fine when pushing accelerater, but soon as i put it in drive or reverse, i carnt rev the engine,it only idles. help thanks 07543472340