Sounds to me like what Curmudgeon said, and you may be able to get it to start with a bit of bush mechanics. It may mean that the sprag clutch is a bit stuck. Sometimes if you put it in gear and rock it back and forth, it may free up or failing that, if there's a hill, or a buddy to push, try clutch/bump starting it. This may free up the throw out cog in the starter. Don't try it in 1st, use 2nd or maybe 3rd gear , get up to a reasonable speed then sit down hard on the seat as you let the clutch out.
Mick