Error 010511: OptimalPathAsLine requiring Back Link, not Back Direction raster

[BrodyManquen1]

Hello,

I am trying to create a least-cost path with the OptimalPathAsLine tool using arcpy, withinputs created by the DistanceAccumulation tool, both in the Spatial Analyst package.

The Distance Accumulation back direction output ranges from 0-360, according to the tool reference. The input back direction raster for the Optimal Path as line tool is the same.

However, when running the tool, I get the following error: 

ExecuteError: Error 010511: Internal error in cost path tracing: backlink raster values must be in range [0..255]...Failed to execute (OptimalPathAsLine).

This code worked approximately 2 weeks ago. I have updated my ArcGIS to 3.4.0. 

To my knowledge, the back link raster is not able to be created by the Distance Accumulation tool, and the older Cost Distance tool that created it is now deprecated.

Any help resolving this would be greatly appreciated!

[DanPatterson]

Cost Back Link (Spatial Analyst)—ArcGIS Pro | Documentation

it is deprecated and will be removed in a future release, but it is still available now

under Distance Toolset, Legacy 

[BrodyManquen1 · Accepted solution]

Thanks for the response. 

With more troubleshooting, I realized it was a problem with my input destination points. One of the destination points was the origin (due to a change in origin) and the overlap caused error.