The problem is that the geometries have been created using curves, which is not supported by a lot of the underlying toolsets which Biotics 5 relies upon.

I discovered this by using the FeaturesToJson tool in the Conversion toolbox to convert the first feature in the sf_poly layer to JSON. This allowed me to easily inspect the feature's geometry, which looked like:

  "geometry" : {
        "curveRings" : [
          [
            [
              1387383.5529761985,
              11853366.064637803
            ],
            {
              "a" : [
                [
                  1387383.5529761985,
                  11853366.064637803
                ],
                [
                  1387470.4902280532,
                  11852194.206690112
                ],
                0,
                1
              ]
            }
          ]
        ]
      }

Use the Densify tool in the Editing Tools toolbox to replace the curves with line segments, which resolves the problem and allows successful creation in Biotics. http://desktop.arcgis.com/en/arcmap/10.5/tools/editing-toolbox/densify.htm