Error on plugin when seeing cart

Hi, I’ve installed your WooCommerce Category Discount plugin and I’m getting a lot of errors like this. What’s happening?

Error Details
=============
An error of type E_ERROR was caused in line 627 of the file
/var/www/html/wp-content/plugins/wc-category-discount/src/DiscountRules.php.
Error message: Uncaught Error: Unsupported operand types in
/var/www/html/wp-content/plugins/wc-category-discount/src/DiscountRules.php:627
Stack trace:
#0 /var/www/html/wp-includes/class-wp-hook.php(284):
Wcd\DiscountRules\DiscountRules->minMaxDiscountRule()
#1 /var/www/html/wp-includes/class-wp-hook.php(310):
WP_Hook->apply_filters(NULL, Array)
#2 /var/www/html/wp-includes/plugin.php(465): WP_Hook->do_action(Array)
#3 /var/www/html/wp-content/plugins/woocommerce/includes/class-wc-cart.php(1213):
do_action(‘woocommerce_bef…’, Object(WC_Cart))
#4 /var/www/html/wp-content/plugins/woocommerce/includes/class-wc-cart-session.php(163):
WC_Cart->calculate_totals()
#5 /var/www/html/wp-includes/class-wp-hook.php(286):
WC_Cart_Session->get_cart_from_session(”)
#6 /var/www/html/wp-includes/class-wp-hook.php(310):
WP_Hook->apply_filters(NULL, Array)
#7 /var/www/html/wp-includes/plugin.php(465): WP_Hook->do_action(Array)
#8 /var/www/html/wp-settings.php(546): do_action(‘wp_loaded’)