I am running GeoHMS (version 10.1.0.42) on ArcGIS 10.1, and got same error message while running the Longest Flow Path. The error message is listed below:
WARNING 010353: The environmental cell size is ignored.
at ESRI.ArcGIS.Geometry.ITopologicalOperator.Intersect(IGeometry other, esriGeometryDimension resultDimension)
at ESRI.APWR.ApHydro.ArcHydroOp.ComputeLongestFlowpath(ApLayers apLayers, Int32 debug, ITrackCancel& trackcancel, IGPMessages& messages, String& exMessage, IRaster costRaster)
Failed to execute (LongestFlowpath).
Failed at Mon May 20 11:34:22 2013 (Elapsed Time: 3 hours 17 minutes 11 seconds)
If anyone has a solution, please post it here. Thanks.
Tenia el mismo error 010353 y pude solucionarlo proyectando nuevamente los archivos de entrada raster y vectorial) en un mismo sistema de coordenadas.