I can't check the rideable and forward movement control boxs together without having an error

hi, 

Im making a mod which add a surf board and i want to make it act like a boat so I followed your yt tutorial but whenever I check the rideable box and forward movement control box and then click save mod element I get an error saying "Your workspace contains mod elements that don't compile propely."

if you have a solution I'm open,

thx