Azure Function calling exe error code 216

Question

I am attempting to call an exe with Azure Functions, and it was failing with Error Code 216. Another exe works fine.

Both executables are compiled with Delphi, and I had access to the source code for both. After a few debugging attempts I found that if I comment out FastMM4 in the uses block the exe that was returning Error Code 216 works.

So to make this a question why would fastmm4 cause an error 216 in Azure Functions?

I'm adding the minimum code to reproduce the error

Delphi Code:

program test;
{$D+,L+}

uses
  FastMM4,
  Windows,
  Classes;

begin
  Writeln('1');
end.

In the Azure Function: #r "Newtonsoft.Json"

using System.Diagnostics;
using System.Net;
using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;
using Newtonsoft.Json;

public static async Task<IActionResult> Run(HttpRequest req, ILogger log, ExecutionContext context)
{
    log.LogInformation("C# HTTP trigger function processed a request.");

    string name = req.Query["name"];

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    dynamic data = JsonConvert.DeserializeObject(requestBody);
    name = name ?? data?.name;

    string responseMessage = Runexe();
  
    return new OkObjectResult(responseMessage);
}

private static string Runexe() {
    Process p = new Process();
    p.StartInfo.UseShellExecute = false;
    p.StartInfo.RedirectStandardOutput = true;
    p.StartInfo.FileName = "d:\\test.exe";
    p.StartInfo.Arguments = "";
    p.Start();
    string output = p.StandardOutput.ReadToEnd();
    p.WaitForExit();

    output = p.StartInfo.FileName + " " + p.StartInfo.Arguments + "\r\n" + output;
    return  output;
}

Error in Azure is d:\home\test.exe Runtime error 216 at 00413D13