I get this error when logging into a site with most updated version of both plugins:
Warning: Creating default object from empty value in /home/*sitename*/public_html/wp-content/plugins/woocommerce/includes/wc-cart-functions.php on line 61
Warning: Cannot modify header information - headers already sent by (output started at /home/*sitename*/public_html/wp-content/plugins/woocommerce/includes/wc-cart-functions.php:61) in /home/*sitename*/public_html/wp-includes/pluggable.php on line 1121
However, I'm logged in. After this error, if I replace the address in my browser to *sitename*/wp-admin - I go right to the dashboard.
I have this problem on several other sites as well. I want to keep using your plugin (because it's AWESOME), but I need to get this working.