Generating a DLL from a Simulink model with S-Function and using it in Unity 3D - unity3d

Question

I'm trying to generate a DLL for a Simulink model with an S function and use that in Unity 3D. To try a simple example, I just made a model with an S-function that multiplies the input value by 2.
I've generated the DLL of this using the Embedded Coder feature. The code generated contains the essential function as follows:
void S_function_tlc_try_step(RT_MODEL_S_function_tlc_try_T *const
S_function_tlc_try_M, real_T S_function_tlc_try_U_x, real_T
*S_function_tlc_try_Y_y)
{
/* local block i/o variables */
real_T rtb_Level2MATLABSFunction1;
/* M-S-Function: '<Root>/Level-2 MATLAB S-Function1' incorporates:
* Inport: '<Root>/x'
*/
/* Multiply input by two */
rtb_Level2MATLABSFunction1 = S_function_tlc_try_U_x * 2.0;
/* Outport: '<Root>/y' */
*S_function_tlc_try_Y_y = rtb_Level2MATLABSFunction1;
/* Update absolute time for base rate */
/* The "clockTick0" counts the number of times the code of this task has
* been executed. The absolute time is the multiplication of "clockTick0"
* and "Timing.stepSize0". Size of "clockTick0" ensures timer will not
* overflow during the application lifespan selected.
*/
S_function_tlc_try_M->Timing.t[0] =
((time_T)(++S_function_tlc_try_M->Timing.clockTick0)) *
S_function_tlc_try_M->Timing.stepSize0;
UNUSED_PARAMETER(S_function_tlc_try_M);
}
The script in Unity is as follows:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Runtime.InteropServices;
public class Sfunctiontry : MonoBehaviour
{
public double input, output;
double constant;
[DllImport("S_function_tlc_try_win64")]
static extern void S_function_tlc_try_step(double constant, double inp, ref double outp);
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
S_function_tlc_try_step(constant, input, ref output);
Debug.Log("Multiplying by 2");
print(output);
}
}
However whenever I attach this to an object and execute, Unity crashes. It works fine when I'm using the DLL of a model without any S-function.
Is there a solution for this? Any leads would be great.
Thanks in advance.