Android Stockfish chess engine error on call

Hi,
I am trying to call the stockfish chess engine (stockfish-10-armv7) from android but getting an error (mono-io-layer-error (5)) when doing the new process at runtime. The PC build worked fine.The engine needs to be run as a detached process and the communication is done via the input output stream. Does anyone know what this mono-io-layer-error (5) is about?

 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using UnityEngine;
 using UnityEngine.Networking;
 using UnityEngine.Android;
 
 
 public static class StockFish
 {
 
     public static Process mProcess;
     public static string engineText = "";
 
     public static void StartEngine()
     {
 
         engineLog("datapath: " + Application.dataPath);        
         engineLog("Streamingpath: " + Application.streamingAssetsPath);
         engineLog("Persist path : " + Application.persistentDataPath);
         //
         string sfBin = "stockfish-10-armv7";
         string sfPathFile = Path.Combine(Application.persistentDataPath, sfBin);
 
         string sfPathAsset = Path.Combine(Application.streamingAssetsPath, sfBin);
 
         loadWeb(sfPathAsset, sfPathFile);
         if (!File.Exists(sfPathFile))
         {
             engineLog("-------FILE NOT FOUND--------------------");
             return;
         }
         else
         {
             engineLog("FILE EXISTS -------------------------------");
         }
         try
         {
             mProcess = new Process();
             ProcessStartInfo si = new ProcessStartInfo()
             {
                 FileName = sfPathFile,
                 UseShellExecute = false,
                 CreateNoWindow = true,
                 RedirectStandardError = true,
                 RedirectStandardInput = true,
                 RedirectStandardOutput = true
             };
             mProcess.StartInfo = si;
             mProcess.OutputDataReceived += new DataReceivedEventHandler(MProcess_OutputDataReceived);
             mProcess.Start();
             mProcess.BeginErrorReadLine();
             mProcess.BeginOutputReadLine();
 
         }
         catch (Exception e)
         {
             engineLog("ERROR Process:" + e.Message);
             return;
         }
         engineLog("------RUN OK----------------");
         UciCmd("uci");
         UciCmd("isready");
         //SendLine("position fen " + forsythEdwardsNotationString);
         //SendLine("go movetime 5000");
 
 
     }
     public static void loadWeb(string inFile, string outFile)
     {
         var loadingRequest = UnityWebRequest.Get(inFile);
 
         loadingRequest.SendWebRequest();
         while (!loadingRequest.isDone)
         {
             if (loadingRequest.isNetworkError || loadingRequest.isHttpError)
             {
                 engineLog("While network error");
                 break;
             }
         }
         if (loadingRequest.isNetworkError || loadingRequest.isHttpError)
         {
             engineLog("network error");
         }
         else
         {
             try
             {
                 File.WriteAllBytes(outFile, loadingRequest.downloadHandler.data);
             }
             catch (Exception e)
             {
                 engineLog("ERROR File Write:" + e.Message);
                 return;
             }
 
         }
     }
     public static void engineLog(string engString)
     {
         engineText = engineText + engString + "\n";
     }
     public static void UciCmd(string command)
     {
         mProcess.StandardInput.WriteLine(command);
         mProcess.StandardInput.Flush();
     }
 
     private static void MProcess_OutputDataReceived(object sender, DataReceivedEventArgs e)
     {
         engineLog(e.Data.ToString());
     }
 
 
 }