Error "Cannot read property 'checkImageKey'" in Sprite.loadTexture

[eu_genes]

I have code

var SpriteOne = function(game) {  Phaser.Group.call(this, game);  this.sprite_one = this.create(30, 50, 'sprite_one');};SpriteOne.prototype = Object.create(Phaser.Group.prototype);  SpriteOne.prototype.constructor = SpriteOne;  

and where complite Sprite.loadTexture i  get error Cannot read property 'checkImageKey in line phaser.js:34716

What is my problem?