Hello Vasyl Savchyn,
Thanks for reaching out to us.
Make sure that the country settings are configured correctly in your WooCommerce settings. To do this, go to the WooCommerce settings page, click on the General
tab, and check that the default country is set correctly.
Also this error occurs when the country field is disabled/removed in either billing or shipping section in the plugin settings. Please note that when you provide validation for the state field or zip code field in any section, it is mandatory to have an active country field.
If the country field is disabled, could you please enable the fields and verify from your side?
Best Regards.