Image file doesn't load properly

In the stage, when I change the image file from platform_1.png to platform_2.png, and preview the program in Workspaces, the file platform_2.png loads properly and is displayed on the screen, but all the platforms that are platform_1.png don't load - they're just shown as black squares with a green outline and diagonal line. What is this, and how do I fix it? Here's the code to it:

// define variables var game; var player; var platforms; var badges; var items; var cursors; var jumpButton; var text; var winningMessage; var won = false; var currentScore = 0; var winningScore = 100;

// add collectable items to the game function addItems() { items = game.add.physicsGroup(); createItem(375, 400, 'coin'); createItem(575, 500, 'coin'); createItem(225, 500, 'coin'); createItem(100, 250, 'coin'); createItem(575, 150, 'coin'); createItem(525, 300, 'coin'); createItem(650, 250, 'coin'); createItem(225, 200, 'coin'); createItem(375, 100, 'coin'); }

// add platforms to the game function addPlatforms() { platforms = game.add.physicsGroup(); platforms.create(450, 550, 'platform'); platforms.create(100, 550, 'platform'); platforms.create(300, 450, 'platform'); platforms.create(250, 150, 'platform'); platforms.create(50, 300, 'platform'); platforms.create(150, 250, 'platform'); platforms.create(650, 300, 'platform'); platforms.create(550, 200, 'platform'); platforms.create(300, 450, 'platform'); platforms.create(400, 350, 'platform'); platforms.setAll('body.immovable', true); }

// create a single animated item and add to screen function createItem(left, top, image) { var item = items.create(left, top, image); item.animations.add('spin'); item.animations.play('spin', 10, true); }

// create the winning badge and add to screen function createBadge() { badges = game.add.physicsGroup(); var badge = badges.create(750, 400, 'badge'); badge.animations.add('spin'); badge.animations.play('spin', 10, true); }

// when the player collects an item on the screen function itemHandler(player, item) { item.kill(); currentScore = currentScore + 10; if (currentScore === winningScore) { createBadge(); } }

// when the player collects the badge at the end of the game function badgeHandler(player, badge) { badge.kill(); won = true; }

// setup game when the web page loads window.onload = function () { game = new Phaser.Game(800, 600, Phaser.AUTO, '', { preload: preload, create: create, update: update, render: render });

// before the game begins function preload() { game.stage.backgroundColor = '#5db1ad';

//Load images
game.load.image('platform1', 'platform_1.png');
game.load.image('platform2', 'platform_2.png');

//Load spritesheets
game.load.spritesheet('player', 'chalkers.png', 48, 62);
game.load.spritesheet('coin', 'coin.png', 36, 44);
game.load.spritesheet('badge', 'badge.png', 42, 54);

}

// initial game set up function create() { player = game.add.sprite(50, 600, 'player'); player.animations.add('walk'); player.anchor.setTo(0.5, 1); game.physics.arcade.enable(player); player.body.collideWorldBounds = true; player.body.gravity.y = 500;

addItems();
addPlatforms();

cursors = game.input.keyboard.createCursorKeys();
jumpButton = game.input.keyboard.addKey(Phaser.Keyboard.SPACEBAR);
text = game.add.text(16, 16, "SCORE: " + currentScore, { font: "bold 24px Arial", fill: "white" });
winningMessage = game.add.text(game.world.centerX, 275, "", { font: "bold 48px Arial", fill: "white" });
winningMessage.anchor.setTo(0.5, 1);

}

// while the game is running function update() { text.text = "SCORE: " + currentScore; game.physics.arcade.collide(player, platforms); game.physics.arcade.overlap(player, items, itemHandler); game.physics.arcade.overlap(player, badges, badgeHandler); player.body.velocity.x = 0;

// is the left cursor key presssed?
if (cursors.left.isDown) {
  player.animations.play('walk', 10, true);
  player.body.velocity.x = -300;
  player.scale.x = - 1;
}
// is the right cursor key pressed?
else if (cursors.right.isDown) {
  player.animations.play('walk', 10, true);
  player.body.velocity.x = 300;
  player.scale.x = 1;
}
// player doesn't move
else {
  player.animations.stop();
}

if (jumpButton.isDown && (player.body.onFloor() || player.body.touching.down)) {
  player.body.velocity.y = -400;
}
// when the player winw the game
if (won) {
  winningMessage.text = "YOU WIN!!!";
}

}

function render() {

}

};

Hope someone can fix it OTL