If you are having issue with OpenTable form then you will need to change the OpenTable domain extension.

1. Install and active child theme ( for easy update in the future ).

2. Add this code into your child theme folder :

add_filter( 'wpc_opentable_url', function() { return 'http://www.opentable.co.uk'; } );

You can change the OpenTable domain extension with your country, for example: http://www.opentable.co.uk, http://www.opentable.de …