We have changed the workflow for generating thethe raster representation of known vector streams in Ac Hydro Tools both in ArcMap and ArcGIS Pro.
Internally, the tool still handles both raster and vector input streams. However the UI for the tool in the tbx toolbox only allows to set one parameter type (we picked rasterlayer). For more context, a Python toolbox would allow you to set up multiple types so you can select either a vector or a raster layer, but then it has other limitations...
Basically if you want to use an input vector, you can just modify the parameter type in the tool ui to feature layer and it will then work (Run ArcMap as admin and you can modify the toolbox).
However, the recommended approach is to use first the tool Create Drainage Line Structures to generate the raster stream (Output Streak Link Raster - strlnk by default). Then use that raster as input to DEM Reconditioning or Build Walls.
I am currently working on modifying the interface so that it says raster only for those. For now the back door is still available to use vector stream but it is not the recommended approach.
Christine Dartiguenave
Esri Water Resources Team