Not sure what the exact error was, I apologize as the notification flashed quickly and having a site down I was working quickly to resolve it.
The fatal error log in woocommerce does show the following, however:
2017-12-22T15:28:13+00:00 CRITICAL Uncaught Error: Call to undefined function wc_print_notices() in /home/public_html/wp-content/themes/CNCFab-v2/woocommerce/wishlist-view.php:78
Stack trace:
#0 /home/public_html/wp-content/plugins/yith-woocommerce-wishlist-premium/includes/functions.yith-wcwl.php(95): include()
#1 /home/public_html/wp-content/plugins/yith-woocommerce-wishlist-premium/templates/wishlist.php(16): yith_wcwl_get_template('wishlist-view.p...', Array)
#2 /home/public_html/wp-content/plugins/yith-woocommerce-wishlist-premium/includes/functions.yith-wcwl.php(95): include('/home/cncfab65/...')
#3 /home/public_html/wp-content/plugins/yith-woocommerce-wishlist-premium/includes/class.yith-wcwl-shortcode.php(301): yith_wcwl_get_template('wishlist.php', Array, true)
#4 /home/public_html/wp-includes/shortcodes.php(319): YITH_WCWL_Shortcode::wishlist(Array, '', 'yith_wcwl_wishl...')
#5 [internal function]: do_shortcode_tag(Array)
#6 /home/public_html/wp-includes/shortcodes.php(19
You might try to recreate the error by updating/activating woocommerce with the Advanced Reviews plugin active. It occured on at least 2 other websites I managed, which are using the same FREE plugin version.
In the above error log we are using YITH Wishlist Premium.
