I am writing code for a window in DirectX, but I experienced an error while compiling.

The error would pop up in a box that says “Exception thrown” alongside the following details:

Exception thrown at 0x00007FFAF7F7C8EA (ntdll.dll) in BlankWindow.exe: 0xC0000005: Access violation reading location

Why does this happen? I have no clue.

Here is my code:

#include <Windows.h>

#define MAX_NAME_STRING 256
#define hInstance() GetModuleHandle(NULL)

WCHAR WindowClass[MAX_NAME_STRING];
WCHAR WindowTitle[MAX_NAME_STRING];

int WindowWidth;
int WindowHeight;

int CALLBACK WinMain(
    HINSTANCE hInstance,
    HINSTANCE,
    LPSTR lpCmdLine,
    INT nCmdShow
)
{

    // Init global vars

    wcscpy_s(WindowClass, TEXT("TutorialOneClass"));
    wcscpy_s(WindowTitle, TEXT("myWindow"));

    WindowWidth = 1280;
    WindowHeight = 720;

    // Create window class

    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;

    wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);

    wcex.hIcon = LoadIcon(0, IDI_APPLICATION);
    wcex.hIconSm = LoadIcon(0, IDI_APPLICATION);

    wcex.lpszMenuName = WindowClass;

    wcex.lpszMenuName = nullptr;

    wcex.hInstance = hInstance();

    wcex.lpfnWndProc = DefWindowProc;

    RegisterClassEx(&wcex);

    // Create and display our window

    HWND hWnd = CreateWindow(WindowClass, WindowTitle, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, WindowWidth, WindowHeight, 
        nullptr, nullptr, hInstance(), nullptr);

    if (!hWnd)
    {
        MessageBox(0, L"Failed to create window! Sucks for you!", 0, 0);
        return 0;
    }

    ShowWindow(hWnd, SW_SHOW);

    // Listen for message events

    MSG msg = { 0 };
    while (msg.message != WM_QUIT)
    {
        if (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return 0;
}