C++ DLL Crashes MS ACCESS

[RCM LittleC]

This is my first C++ adventure. It is a .NET DLL that I want to call functions from within VBA (MS Access 2007). So after a couple of days of banging my head, I ended up with this code, which compiles without any issues. I have /cls enabled in order to use the .NET namespaces, and use an export.def file for the compiler.

When I call the (sole) function via VBA, access immediately crashes! LOL! I have mixed emotions: I'm SO happy I finally got the DLL built and was able to call the function (I had some issues at first with 'decorated' exports).

Can anyone tell me what I have done wrong to crash Access?

Main.cpp

#include <string>
#include <stdlib.h>
#include <msclr\marshal_cppstd.h> 
 
using namespace msclr::interop;
using namespace std;
using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Security::Cryptography;

_declspec(dllexport) string Encrypt(string strText, string strEncrKey)
{
	// Initialize a Byte array with 8 bytes for Initial Vector of the Encryptor
	array<Byte>^ IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
	
	//Handle exceptions
	try
	{
//Convert std:string to System:String for the GetBytes() Function
//Get the UTF8 Encoding for the System:String
	String^ s = gcnew String(strEncrKey.c_str());
	array<Byte>^ byKey = Encoding::UTF8->GetBytes(s);

//Convert std:string to System:String for the GetBytes() Function
//Get the UTF8 Encoding for the System:String
	String^ s1 = gcnew String(strText.c_str());
	array<Byte>^ InputByteArray = Encoding::UTF8->GetBytes(s1);

//Now create an instance of DESCryptoServiceProvider & MemoryStream and cross your fingers
	DESCryptoServiceProvider^ des = gcnew DESCryptoServiceProvider;
	MemoryStream^ ms = gcnew MemoryStream;

//Ok, here we go with the Cryptostream object! It took a little work, had to change the definition of IV
//from Byte IV[] = {x,x,x} to array<Byte>^ IV = {x,x,x}
	CryptoStream^ cs = gcnew CryptoStream(ms, des->CreateEncryptor(byKey, IV), CryptoStreamMode::Write);
	cs->Write(InputByteArray, 0, InputByteArray->Length);
	cs->FlushFinalBlock();

//Convert the result from System::String to std::string and return it
	String^ s2 = gcnew String(Convert::ToBase64String(ms->ToArray()));
	string s3 = marshal_as<std::string>(s2);
	return s3;
	}
	catch (exception& ex)
	{
	return ex.what();
	}
}

export.def

LIBRARY RCMcrypt
EXPORTS
Encrypt @1

[kbw]

You may need to use plain C strings (LPCTSTR) as the input parameters, rather than std::string. I'm sure VB won't know what an STL string is.