WIN API не регистрирует класс окна)

#include <windows.h>
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
 
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    HWND hMainWnd;
    wchar_t szClassName[] = L"MyClass";
    MSG msg;
    WNDCLASSEX wc;
 
    wc.cbSize        = sizeof(wc);
    wc.style         = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = L"MyClass";
    wc.hIconSm       = LoadIcon(NULL,IDI_APPLICATION);
 
    if(!RegisterClassEx(&wc)) {
        MessageBox(NULL, L"Cannot Register Class!", L"Error!", MB_OK);
        return 0;
    }
 
    hMainWnd = CreateWindow(szClassName, L"Hello word app",
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,
        0, CW_USEDEFAULT, 0, (HWND)NULL, (HMENU)NULL,
        (HINSTANCE)hInstance, NULL);
 
    if(!hMainWnd) {
        MessageBox(NULL, L"Cannot crate main windows!", ERROR, MB_OK);
        return 0;
    }
 
    ShowWindow(hMainWnd, nCmdShow);
 
 
    while(GetMessage(&msg, NULL,  0 , 0)){
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
 
    return msg.wParam;
}
 
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hDC;
    PAINTSTRUCT ps;
    RECT rect;
    switch (uMsg)
    {
    case WM_PAINT:
        hDC = BeginPaint(hWnd, &ps);
        GetClientRect(hWnd, &rect);
        DrawText(hDC, L"Hello, Word,", -1, &rect,
            DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        EndPaint(hWnd, &ps);
        break;
    case WM_CLOSE:
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}