Strange "Freeze" - c++

Question

When I compile and run application, for example this source code (from tutorial, I had to fix this code, ex. big letters in names of methods):
#include <SFML\Graphics.hpp>
#include <Box2D\Box2D.h>
/** We need this to easily convert between pixel and real-world coordinates*/
static const float SCALE = 30.f;
/** Create the base for the boxes to land */
void CreateGround(b2World& World, float X, float Y);
/** Create the boxes */
void CreateBox(b2World& World, int MouseX, int MouseY);
int main()
{
/** Prepare the window */
sf::RenderWindow Window(sf::VideoMode(800, 600, 32), "Test");
Window.SetFramerateLimit(60);
/** Prepare the world */
b2Vec2 Gravity(0.f, 9.8f);
b2World World(Gravity);
CreateGround(World, 400.f, 500.f);
/** Prepare textures */
sf::Texture GroundTexture;
sf::Texture BoxTexture;
GroundTexture.LoadFromFile("ground.png");
BoxTexture.LoadFromFile("box.png");
while (Window.IsOpened())
{
if (sf::Mouse::IsButtonPressed(sf::Mouse::Left))
{
int MouseX = sf::Mouse::GetPosition(Window).x;
int MouseY = sf::Mouse::GetPosition(Window).y;
CreateBox(World, MouseX, MouseY);
}
World.Step(1/60.f, 8, 3);
Window.Clear(sf::Color::White);
int BodyCount = 0;
for (b2Body* BodyIterator = World.GetBodyList(); BodyIterator != 0; BodyIterator = BodyIterator->GetNext())
{
if (BodyIterator->GetType() == b2_dynamicBody)
{
sf::Sprite Sprite;
Sprite.SetTexture(BoxTexture);
Sprite.SetOrigin(16.f, 16.f);
Sprite.SetPosition(SCALE * BodyIterator->GetPosition().x, SCALE * BodyIterator->GetPosition().y);
Sprite.SetRotation(BodyIterator->GetAngle() * 180/b2_pi);
Window.Draw(Sprite);
++BodyCount;
}
else
{
sf::Sprite GroundSprite;
GroundSprite.SetTexture(GroundTexture);
GroundSprite.SetOrigin(400.f, 8.f);
GroundSprite.SetPosition(BodyIterator->GetPosition().x * SCALE, BodyIterator->GetPosition().y * SCALE);
GroundSprite.SetRotation(180/b2_pi * BodyIterator->GetAngle());
Window.Draw(GroundSprite);
}
}
Window.Display();
}
return 0;
}
void CreateBox(b2World& World, int MouseX, int MouseY)
{
b2BodyDef BodyDef;
BodyDef.position = b2Vec2(MouseX/SCALE, MouseY/SCALE);
BodyDef.type = b2_dynamicBody;
b2Body* Body = World.CreateBody(&BodyDef);
b2PolygonShape Shape;
Shape.SetAsBox((32.f/2)/SCALE, (32.f/2)/SCALE);
b2FixtureDef FixtureDef;
FixtureDef.density = 1.f;
FixtureDef.friction = 0.7f;
FixtureDef.shape = &Shape;
Body->CreateFixture(&FixtureDef);
}
void CreateGround(b2World& World, float X, float Y)
{
b2BodyDef BodyDef;
BodyDef.position = b2Vec2(X/SCALE, Y/SCALE);
BodyDef.type = b2_staticBody;
b2Body* Body = World.CreateBody(&BodyDef);
b2PolygonShape Shape;
Shape.SetAsBox((800.f/2)/SCALE, (16.f/2)/SCALE);
b2FixtureDef FixtureDef;
FixtureDef.density = 0.f;
FixtureDef.shape = &Shape;
Body->CreateFixture(&FixtureDef);
}
My application is "not responding" after few seconds. The window turns to grey but, everything works! Objects are moving and all interactions are working. What is the problem?