Coursepress pro -submenu link not working

On the unit page there is a submenu at the top with links to the notifications page etc. The links do not work, they are missing a preceding forward slash for some reason. I've tried refreshing permalinks etc - I'm guessing there's an error in the code on whichever php doc contains the submenu function.

I don't mind playing around with the code if you can point me in the right direction?