I can confirm. This AA ability does not work for me either and I get the same message.I use the skill correctly and also have my Melee pets outside etc.
I've bugged this a couple of times starting right after ROS went live. So it's not like they aren't aware, unless /bugs go into a black hole. Apparently not enough of an issue.
a necro probably casted Grasping Bones on Shadowstep and sent it into a void for the next year or so...