I just experienced the same issue. It looks like the picture shows a repair in progress. How did it work out?
I'll up date my progress.
Around 60 hours I experienced what the others commented on with the loose knuckles. I at 290 hours with this issue.
Happy Tractoring !
On my RK24 i found it is the brake switch. I have had the issue you described occasionally. I turn the key and release the brake peddle slowly until it cranks.