Error when editing page with shortcode

When I try to save the shortcode [xoo_wsc_cart] I get this error:

Notice: Trying to get property of non-object in /project/wp-content/plugins/woocommerce-side-cart-premium/public/partials/xoo-wsc-shortcode.php on line 12

Fatal error: Uncaught Error: Call to a member function get_cart_contents_count() on null in /project/wp-content/plugins/woocommerce-side-cart-premium/public/partials/xoo-wsc-shortcode.php:19
Stack trace:
#0 /project/wp-content/plugins/woocommerce/includes/wc-core-functions.php(211): include()
#1 /project/wp-content/plugins/woocommerce-side-cart-premium/xoo-wsc.php(107): wc_get_template(‘xoo-wsc-shortco…’, ”, ”, ‘/home/alberto/w…’)
#2 /project/wp-includes/shortcodes.php(319): xoo_wsc_cart_shortcode_func(”, ”, ‘xoo_wsc_cart’)
#3 [internal function]: do_shortcode_tag(Array)
#4 /project/wp-includes/shortcodes.php(197): preg_replace_callback(‘/\\[(\\[?)(xoo_ws…’, ‘do_shortcode_ta…’, ‘[xoo_wsc_cart]’)
#5 /project/wp-content/themes/Divi/includes/builder/class-et-builder-element.php(1507): do_shortcode(‘[xoo_wsc_cart]’) #6 /project/wp-includes/shortcodes.php(319): ET_Builder_Eleme in /project/wp-content/plugins/woocommerce-side-cart-premium/public/partials/xoo-wsc-shortcode.php on line 19