How to deal with 0xC0000409 crash running tensorflow retrain when trying to intercept with c#?

My goal is to create a small gui for tensorflow. My command in DOS is

"C:\pythonpath\python.exe" "E:\retrainpath\retrain.py" --image_dir "D:\picturepath"

which works as it should

I c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\stream_executor\dso_loader.cc:128] successfully opened CUDA library cublas64_80.dll locally
I c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\stream_executor\dso_loader.cc:128] successfully opened CUDA library cudnn64_5.dll locally
I c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\stream_executor\dso_loader.cc:128] successfully opened CUDA library cufft64_80.dll locally
I c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\stream_executor\dso_loader.cc:128] successfully opened CUDA library nvcuda.dll locally
I c:\tf_jenkins\home\workspace\release-win\device\gpu\os\windows\tensorflow\stream_executor\dso_loader.cc:128] successfully opened CUDA library curand64_80.dll locally
>> Downloading inception...

Yet trying to intercept the output in c# does not, using

private void button1_Click(object sender, EventArgs e)
{
    ParameterizedThreadStart pts = new ParameterizedThreadStart(trainieren);
    Thread thread = new Thread(pts);
    thread.Start(@"D:\picturepath");
}

string python = @"C:\pythonpath\python.exe";
string retrain = @"E:\retrainpath\retrain.py";


void trainieren(Object bildv)
{
    this.Invoke((MethodInvoker)delegate
    {
        button1.Enabled = false;
    });
    string bildverzeichnis = (string)bildv;
    string ApplicationPath = python;
    string ApplicationArguments = "\""+retrain + "\" --image_dir \"" + bildverzeichnis+"\"";
    Console.WriteLine(ApplicationPath + " " + ApplicationArguments);
    Process ProcessObj = new Process();
    ProcessObj.StartInfo.FileName = ApplicationPath;
    ProcessObj.StartInfo.Arguments = ApplicationArguments;
    ProcessObj.StartInfo.UseShellExecute = false;
    ProcessObj.StartInfo.RedirectStandardOutput = true;
    ProcessObj.StartInfo.RedirectStandardError = true;
    ProcessObj.StartInfo.RedirectStandardInput = true;
    ProcessObj.StartInfo.CreateNoWindow = true;
    ProcessObj.ErrorDataReceived += build_ErrorDataReceived;
    ProcessObj.OutputDataReceived += build_ErrorDataReceived;

    ProcessObj.EnableRaisingEvents = true;
    ProcessObj.Start();
    ProcessObj.BeginOutputReadLine();
    ProcessObj.BeginErrorReadLine();
    ProcessObj.WaitForExit();
    this.Invoke((MethodInvoker)delegate
    {
        button1.Enabled = true;
        this.Text = "Fertig";
    });
    statusInnen("Beendet");
    pb(0, 100, 0);
}

and

void build_ErrorDataReceived(object sender, DataReceivedEventArgs e)
{
    string zeile = e.Data;
    Console.WriteLine(zeile);
}

All that happens when clicking button1 is: button1 becomes disabled and then enabled, the output in the debug window is two empty lines.

I found in the minidump of python that it crashed because of 0xC0000409, a STATUS_STACK_BUFFER_OVERRUN.

Running an alternative file

import sys

s = 'Hello, world.'
print(s)

prints Hello, world. in c#, so it is a problem with tensorflows retrain, but only when called from c#.