Had a similar problem, first trial on new Rev 3 12 months ago,chain jumped after snagging sticky out rock, jammed round gearbox sprocket resulting in sheared adjuster bolt.
That,s the third one today smirked the observer.
Cured this by drilling out holes,tapping M8,and fitting suitable caphead bolts.never a bit of bother since.
Pick up 05 250 next week,any good?