Fatal error: Uncaught Error: Call to undefined function WC() in /var/www/html/wp-content/plugins/mailchimp-for-woocommerce/includes/tracking/class-mailchimp-woocommerce-pixel-tracking.php:368
Stack trace:
#0 /var/www/html/wp-includes/class-wp-hook.php(324): MailChimp_WooCommerce_Pixel_Tracking->hydrate_script_data_from_session(Object(WP))
#1 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#2 /var/www/html/wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#3 /var/www/html/wp-includes/class-wp.php(830): do_action_ref_array('wp', Array)
#4 /var/www/html/wp-includes/functions.php(1336): WP->main('')
#5 /var/www/html/wp-blog-header.php(16): wp()
#6 /var/www/html/index.php(17): require('/var/www/html/w...')
#7 {main}
  thrown in /var/www/html/wp-content/plugins/mailchimp-for-woocommerce/includes/tracking/class-mailchimp-woocommerce-pixel-tracking.php on line 368