WP_DEBUG throws errors wich result in the plugin not working with debugging enabled. Ie. If you develop with debugging on, (to catch and diagnose problems), this plugin wont work - leaving you to give up on it until desperate for a solution bridge GF with CC.
Until a patch is made, simply disable debugging and it works a charm.
A solution which simply never occurred to me . . . . (slow-motion-forehead-smack)
Thread which discusses the Debug catch-22:
Apologies if this issue is posted elsewhere - haven't been able to find a reference to it.