The WooCommerce Price Based on Country 1.5.10 fix release is now available. You can download it onWordPress.org or as an automatic update in your administration panel.
WooCommerce Price Based on Country 1.5.10 fixes several issues related with code improvements and new features introduced by WooCommerce 2.6 “Zipping Zebra”.
Changelog for 1.5.10 is below.
* Fixed - Bug with shippings methods of WooCommerce 2.6
* Fixed: Bug on price filter of WooCommerce 2.6
* Fixed - Check if customer has been initialized in woocommerce_currency hook
* Fixed - Wrong price for variation products when price included tax.