Exception thrown at 0x54FCC405 (sfml-system-d-2.dll) Access violation reading location 0x00000017

#include <SFML\Graphics.hpp>
#include <string>

using namespace sf;
using namespace std;

string calculate()
{
    static Clock clock = Clock();
    static float decimalTime = 0;

    decimalTime += clock.getElapsedTime().asSeconds();

    int decimalTimeIntPart = floorf(decimalTime);
    if (decimalTimeIntPart > decimalTime)
        decimalTimeIntPart--;
    float decimalTimeFractionalPart = decimalTime - decimalTimeIntPart;

    string binaryTimeStr;
    int n = decimalTimeIntPart;
    while (n != 0)
    {
        binaryTimeStr = to_string(n % 2) + binaryTimeStr;
        n = (n - n % 2) / 2;
    }

    binaryTimeStr += ".";
    float m = decimalTimeFractionalPart;
    int t = 4;
    while (m != 0 && t != 0)
    {
        m *= 2;
        if (m >= 1)
        {
            binaryTimeStr += "1";
            m--;
        }
        else
        {
            binaryTimeStr += "0";
        }
        t--;
    }

    clock.restart();
    return binaryTimeStr;
}

int main() 
{
    RenderWindow app(VideoMode(800, 600), "Heyyy!", !Style::Resize + Style::Close);

    Font font;
    font.loadFromFile("VT323-Regular.ttf");

    Text text("", font, 40);
    text.setColor(Color(234, 234, 234));
    text.setPosition(80, 280);

    while (app.isOpen())
    {
        Event e;
        while (app.pollEvent(e))
        {
            if (e.type == Event::Closed)
                app.close();
        }

        app.clear();

        text.setString(calculate());
        app.draw(text);

        app.display();
    }

    return 0;
}

It works in debug mode, but in release mode I get "Exception thrown at 0x550DC405 (sfml-system-d-2.dll) in my_$FML_stuff.exe: 0xC0000005: Access violation reading location 0x00000017."

It looks like my post is mostly code but I don't know what else to write, sorry.

It's because you are linking the debug libraries of SFML when you are running under release mode

sfml-system-d-2.dll 

the -d means debug, those dll without -d is for release mode.

you can also see it here from the documentation of SFML

It is important to link to the libraries that match the configuration: "sfml-xxx-d.lib" for Debug, and "sfml-xxx.lib" for Release. A bad mix may result in crashes.