bullseyedesigns on "WooCommerce Custom Price plugin Settings not updated"

Hi,
I've just installed your plugin with the latest versions of both WordPress and WooCommerce, but whenever I change the settings in the WooCommerce Custom Price plugin and click Save Changes, the changes aren't saved, and they default back to Pre-order & Coming Soon.
Any idea what the problem could be?
Thanks
PS. It's currently on my localhost, so i cannot give an address for it to be looked at.

https://wordpress.org/plugins/woocommerce-custom-price/