error on activation

By the way, I am using WP 4.1.1 and WooCommerce 2.3.7, and this plugin 1.2.
I have resolved this error this way:

user-wallet-main.php line 30: replace

add_action('wp_loaded', array(__CLASS__, 'register_scripts'));
		add_action('wp_loaded', array(__CLASS__, 'register_styles'));
		add_action('init', array(__CLASS__, 'includes'));
		add_action('init', array(__CLASS__, 'register_terms'));
		add_action( 'admin_notices', array($this, 'admin_notice') );

by:

add_action('wp_loaded', array($this, 'register_scripts'));
	add_action('wp_loaded', array($this, 'register_styles'));
	add_action('init', array(__CLASS__, 'includes'));
	add_action('init', array($this, 'register_terms'));
        add_action( 'admin_notices', array($this, 'admin_notice') );

Also, later I have been facing another error related to deprecated woocommerce function and filter certainly due to my fresh version of WooCommerce:

in includes/filters.php line 24

replace:

add_filter ('add_to_cart_redirect ', 'uw_redirect_to_checkout');
function uw_redirect_to_checkout ()
{
	if(isset($_POST['uw_add_product']))
	{
		$product_id = (int) apply_filters('woocommerce_add_to_cart_product_id', $_POST['add-to-cart']);
		if( has_term( 'credit', 'product_cat', $product_id ) )
		{
			global $woocommerce;
			$woocommerce->clear_messages();
			return $woocommerce->cart->get_checkout_url();
		}
}
}

by:

add_filter ('woocommerce_add_to_cart_redirect', 'uw_redirect_to_checkout');
function uw_redirect_to_checkout ()
{
	if(isset($_POST['uw_add_product']))
	{
		$product_id = (int) apply_filters('woocommerce_add_to_cart_product_id', $_POST['add-to-cart']);
		if( has_term( 'credit', 'product_cat', $product_id ) )
		{
			global $woocommerce;
                        wc_clear_notices();
			return $woocommerce->cart->get_checkout_url();
		}
}
}

Thanks a lot, great plugin! Keep updated!

Hello,
The problem persists, the plugin code needs to be updated