Building walls to correct channelized flow in ArcHydro

My current project entails burning in a known river network into a high resolution (10x10m) DEM. In doing so, I’m attempting to build walls to correct for channelized flow in the DEM, in order to eventually execute the flow direction and flow accumulation tools.
I’ve identified two areas where there are man-made channels that don’t follow the DEM. In these places, I created a polygon shapefile for “Inner Walls” and a polyline shapefile for “breakthrough lines” to put in the Build Walls tool.
In the photo below, I depict an initial flow accumulation DEM in blue just to show why I’m building the walls here.

Yet, I keep getting this error below and am not sure what steps to take to resolve it.