CRITICAL Uncaught TypeError

Hi,

Just noticed the log folder is being filled up with fatal-errors log files, with several errors per day:

CRITICAL Uncaught TypeError: Unsupported operand types: string - int in /wp-content/plugins/woocommerce/includes/class-wc-session-handler.php:456
Stack trace:
#0 /wp-content/plugins/woocommerce/includes/class-wc-session-handler.php(324): WC_Session_Handler->get_session()
#1 /wp-content/plugins/woocommerce/includes/class-wc-session-handler.php(96): WC_Session_Handler->get_session_data()
#2 /wp-content/plugins/woocommerce/includes/class-wc-session-handler.php(71): WC_Session_Handler->init_session_cookie()
#3 /wp-content/plugins/svea-checkout-for-woocommerce/inc/Webhook_Handler.php(113): WC_Session_Handler->init()
#4 /wp-content/plugins/svea-checkout-for-woocommerce/inc/Webhook_Handler.php(584): Svea_Checkout_For_Woocommerce\Webhook_Handler::get_cart_session()
#5 /wp-includes/class-wp-hook.php(324): Svea_Checkout_For_Woocommerce\Webhook_Handler->process_push()
#6 /wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#7 /wp-includes/plugin.php(517): WP_Hook->do_action()
#8 /wp-content/plugins/woocommerce/includes/class-wc-api.php(161): do_action()
#9 /wp-includes/class-wp-hook.php(324): WC_API->handle_api_requests()
#10 /wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#11 /wp-includes/plugin.php(565): WP_Hook->do_action()
#12 /wp-includes/class-wp.php(418): do_action_ref_array()
#13 /wp-includes/class-wp.php(813): WP->parse_request()
#14 /wp-includes/functions.php(1336): WP->main()
#15 /wp-blog-header.php(16): wp()
#16 /index.php(17): require('...')
#17 {main}
  thrown i /wp-content/plugins/woocommerce/includes/class-wc-session-handler.php på linje 456