rtMedia error shows in Membership Access Levels

This error message only appears in the Membership "Access Levels" edit screen.

Warning: array_merge(): Argument #2 is not an array in /home/aaa286new/artsartistsartwork.com/wp-content/plugins/buddypress-media/app/admin/RTMediaAdmin.php on line 463

So there would suggest an error is occurring in relation to that plugin but I have no idea what to make of this sort of thing.

Suggestions?