Your theme (Royal Child) contains outdated copies of some WooCommerce template files. These files may need updating to ensure they are compatible with the current version of WooCommerce. You can see which files are affected from the system status page. If in doubt, check with the author of the theme.
What files do I need to update?
Site URL: hidden Theme version: Version: 2.6 WooCommerce version: 2.6.1
You shouldn’t worry about those notices. They won’t affect your site at all. We edited Woocommerce files in wp-content/themes/royal/woocommerce directory and old version may be written in those files. But, please don’t worry, as the original version is written in wp-content/plugins/woocommerce/templates directory.
So you can hide this message.