[Plugin: WooCommerce] Checkout not working

Here is the problem.
When I try to create account on checkout, I get an infinite spinner and when I try to se what is an error, from
/wp-admin/admin-ajax.php?action=woocommerce-checkout
I get an error like this

{"result":"failure","messages":"
\n\t\t\t
Action failed. Please refresh the page and retry.<\/li>\n\t\t\t
First Name<\/strong> is a required field.<\/li>\n\t\t\t
Last Name<\/strong> is a required field.<\/li>\n\t\t\t
Address<\/strong> is a required field.<\/li>\n\t\t\t
Town\/City<\/strong> is a required field.<\/li>\n\t\t\t
Postcode\/Zip<\/strong> is a required field.<\/li>\n\t\t\t
Country<\/strong> is a required field.<\/li>\n\t\t\t
State\/County<\/strong> is a required field.<\/li>\n\t\t\t
Email Address<\/strong> is a required field.<\/li>\n\t\t\t
Phone<\/strong> is a required field.<\/li>\n\t\t\t
Invalid payment method.<\/li>\n\t<\/ul>","refresh":"false"}

But all fields are filled.
Any ideas?

https://www.ads-software.com/extend/plugins/woocommerce/