This.trigger undefined

I’m pretty sure I define trigger right here, but in the debugger it says trigger is undefined.

StopCheck.attributes.add('dice', {type: 'entity'});
StopCheck.attributes.add('manager', {type: 'entity'});

// initialize code called once per entity
StopCheck.prototype.initialize = function() 
{
    this.trigger = this.manager.script.gameManager.removedCoins;
    this.stopped = false;
    this.timer = 0;
};

// update code called every frame
StopCheck.prototype.update = function(dt) 
{
    if(this.stopped === false && this.trigger === true)
    {
        this.timer += dt;
        console.log(this.timer);
        if(this.timer>5)
        {
            this.check();
            this.timer = 0;
        }
    }
};

It means the following code

this.manager.script.gameManager.removedCoins

Evaluates to undefined, which you then assign to this.trigger.

Edit:
Make sure this line is executed after the removedCoins becomes available in gameManager script.