RasterAnalysisTools GenereteRaster Task failed with the error ‘{"messageCode": "RA_120001", "message": "Distributed Raster Analysis failed. ERROR 999999: Error executing function.\nAuthentication token required. (status code 499).\nFailed to execute (GenerateRasterFromRasterFunction).\n."}’, when ‘ColorrampName’ is used in rasterFunction parameter in ArcGIS Enterprise 10.5.1 Image Server.