Using WooCommerce 2.6.1
I cannot delete a product variation for a variable product: the record is still in the database after the ajax call. It seems the ajax call doesn't go through: putting error_log(print_r('remove_variation', true)); doesn't output anything (line 387 in class-wc-ajax.php). The action is added in the constructor of the class. The function public function remove_variation() is just not called.
Has anyone had the same issue, and found a way to make it work?
remove && $variation_product->is_type( 'subscription_variation' ) to solve the problem of un-deletable variations. http://support.woothemes.com/requests/162693 should provide a patch, issue has been reported.