Animate causing app to crash

For some reason, this section of code is causing my app to crash, which is triggered when the user swipes the screen to the left:

    $.toolbar.animate({
        right: 0,
        duration: 500
    });

    $.mainMenu.animate({
        left: -100,
        duration: 500
    });

    $.bottom.animate({
        left: -100,
        duration: 500
    });

Does anybody know why this is causing my app to crash? toolbar, mainMenu and bottom are all views.