Since its introduction in Phase 2, the SoD version of Shadowstep has suffered from frequent “no path available” errors. It seems like this version of Shadowstep uses a pathing logic very similar to that of Charge/Intercept. As a result, the Rogue cannot Shadowstep behind a unit that is standing on a ledge and will instead run into the aforementioned error message.
This isn’t how Shadowstep has worked in TBC or any subsequent expansions, so I doubt it’s intended to be like that. Additionally (and very importantly), Shadowstrike (another new Rogue ability introduced in SoD) has a teleport whose pathing works exactly how Shadowstep would work in TBC and beyond.
Unfortunately it has been incredibly difficult to get any blizzard spokesperson to address this issue. Is the team aware of this interaction, is this intended behaviour or indeed a bug?