This showed up today on a client’s website, running WordPress 4.6.1, Woocommerce 2.6.2, and Storefront 2.1.2 with a child theme. The plugins work, just getting these warnings in the plugins admin panel.
As Benjamin Smith noted above, disabling WooCommerce Helper seems to remove these “no version” warnings. We’ve noticed no system issues otherwise. Wouldn’t be surprised to see an update from WooThemes fairly soon.
This issue was caused by an incorrect conditional which was always failing, due to a recent change we have made. We have now deployed a fix for this in WooCommerce.com so you should no longer be seeing those notices.