Failed to import RSA private key: "Bad Version of provider"

I have a random private key ("C:\tmp\private.key"):

I tried to use the RSACryptoServiceProvider.ImportCspBlob to import it but it failed with the error:

System.Security.Cryptography.CryptographicException: Bad Version of provider.

Full stack trace:

Failed: System.Security.Cryptography.CryptographicException: Bad Version of provider.

   at System.Security.Cryptography.CryptographicException.ThrowCryptographicException(Int32 hr)
   at System.Security.Cryptography.Utils._ImportCspBlob(Byte[] keyBlob, SafeProvHandle hProv, CspProviderFlags flags, SafeKeyHandle& hKey)
   at System.Security.Cryptography.Utils.ImportCspBlobHelper(CspAlgorithmType keyType, Byte[] keyBlob, Boolean publicOnly, CspParameters& parameters, Boolean randomKeyContainer, SafeProvHandle& safeProvHandle, SafeKeyHandle& safeKeyHandle)
   at System.Security.Cryptography.RSACryptoServiceProvider.ImportCspBlob(Byte[] keyBlob)
   at ConsoleApplication3.Program.DecodeRSA(Byte[] data, Int32 c_data) in C:\Users\myuser\Documents\Visual Studio 2015\Projects\myproj\ConsoleApplication3\Program.cs:line 28
   at ConsoleApplication3.Program.Main(String[] args) in C:\Users\myuser\Documents\Visual Studio 2015\Projects\myproj\ConsoleApplication3\Program.cs:line 14
Press any key to continue . . .

Any idea what I am doing wrong?

This is my code:

using System;
using System.Security.Cryptography;

namespace ConsoleApplication3
{
    class Program
    {
        static public byte[] privateKey;
        static void Main(string[] args)
        {
            try
            {
                privateKey = System.IO.File.ReadAllBytes(@"C:\tmp\private.key");
                DecodeRSA(privateKey);
            }
            catch(Exception e)
            {
                Console.WriteLine("Failed: {0}", e);
            }
        }

        static public void DecodeRSA(byte[] data)
        {
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(Program.privateKey);
            }
        }

    }
}

Solution

Thanks to the @Topaco answer, I understood that I need to find the CSP blob and like he mentioned, it is undocumented.

So I just used byte[] a = rsa.ExportCspBlob(true); to get it.
I converted the bytes to base64 and this is a correct key format in base64 that worked for me:

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

It is important to mentioned that I just need that this function will pass successfully because I am working on a blackbox application and I can't change the code, I need to provide it with the right input.