LEGO The Hobbit Bug

Hey, i'm playing lego the hobbit in steam, and recently i discovered a bug in "The Troll Hoard".

Basically when i go to the last part with Radagast in sled, i need to jump in the orc rider and press "X", but after jump in the orc rider if i press X Radagast just fall down, die and back to the sled.

I just cant continue the phase, so i cant take the final minikit in this part, because i need 2 dwarfs to break a wall

Help!!!