Step 1: To fix this issue Create one more class file with name RawPrinterHelper.cs with below definition (Download):

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace POSPrintExample {
 public class RawPrinterHelper {
 // Structure and API declarions:
 [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
 public class DOCINFOA {
 [MarshalAs(UnmanagedType.LPStr)]
 public string pDocName;
 [MarshalAs(UnmanagedType.LPStr)]
 public string pOutputFile;
 [MarshalAs(UnmanagedType.LPStr)]
 public string pDataType;
 }
 [DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, ref IntPtr hPrinter, IntPtr pd);

 [DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool ClosePrinter(IntPtr hPrinter);

 [DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In(), MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

 [DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool EndDocPrinter(IntPtr hPrinter);

 [DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool StartPagePrinter(IntPtr hPrinter);

 [DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool EndPagePrinter(IntPtr hPrinter);

 [DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
 public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, ref Int32 dwWritten);

 // SendBytesToPrinter()
 // When the function is given a printer name and an unmanaged array
 // of bytes, the function sends those bytes to the print queue.
 // Returns true on success, false on failure.
 public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount) {
 Int32 dwError = 0;
 Int32 dwWritten = 0;
 IntPtr hPrinter = new IntPtr(0);
 DOCINFOA di = new DOCINFOA();
 bool bSuccess = false;
 // Assume failure unless you specifically succeed.
 di.pDocName = "My C#.NET RAW Document";
 di.pDataType = "RAW";

 // Open the printer.
 if (OpenPrinter(szPrinterName.Normalize(), ref hPrinter, IntPtr.Zero)) {
 // Start a document.
 if (StartDocPrinter(hPrinter, 1, di)) {
 // Start a page.
 if (StartPagePrinter(hPrinter)) {
 // Write your bytes.
 bSuccess = WritePrinter(hPrinter, pBytes, dwCount, ref dwWritten);
 EndPagePrinter(hPrinter);
 }
 EndDocPrinter(hPrinter);
 }
 ClosePrinter(hPrinter);
 }
 // If you did not succeed, GetLastError may give more information
 // about why not.
 if (bSuccess == false) {
 dwError = Marshal.GetLastWin32Error();
 }
 return bSuccess;
 }

 public static bool SendFileToPrinter(string szPrinterName, string szFileName) {
 // Open the file.
 FileStream fs = new FileStream(szFileName, FileMode.Open);
 // Create a BinaryReader on the file.
 BinaryReader br = new BinaryReader(fs);
 new Byte[fs.Length];
 bool bSuccess = false;
 // Your unmanaged pointer.��3 IntPD���_J�magedBytes = new IntPtr(0);
 int nLength = 0;

 nLength = Convert.ToInt32(fs.Length);
 // R1hd the contents of the file into the array.
���bytQ��9 br.ReadBytes(nLength);
 // Allocate some unmanaged memory for those bytes.
 pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
 // Copy the managed byte array into the unmanaged array.
 Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
 // Send the unmanaged bytes to the printer.
 bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
 // Free the unmanaged memory that you allocated earlier.
 Marshal.FreeCoTaskMem(pUnmanagedBytes);
 return bSuccess;
 }
 public static bool SendStringToPrinter(string szPrinterName, string szString) {
 IntPtr pBytes =
 default (IntPtr);
 Int32 dwCount =
 default (Int32);
 // How many characters are in the string?
 dwCount = szString.Length;
 // Assume that the printer is expecting ANSI text, and then convert
 // the string to ANSI text.
 pBytes = Marshal.StringToCoTaskMemAnsi(szString);
 // Send the converted ANSI string to the printer.
 SendBytesToPrinter(szPrinterName, pBytes, dwCount);
 Marshal.FreeCoTaskMem(pBytes);
 return true;
 }
 }
}

Step 2: Use below code for printing:

 if (File.Exists(".\\tmpPrint.print"))
                File.Delete(".\\tmpPrint.print");
            File.WriteAllBytes(".\\tmpPrint.print", BytesValue);
            RawPrinterHelper.SendFileToPrinter("POS1", ".\\tmpPrint.print");
            try
            {
                File.Delete(".\\tmpPrint.print");
            }
            catch
            {

            }