Description
In new version of ViArt there is a setting 'Percentage Price Type' which allows to calculate price for option as a percentage from another option. The problem is when coping an option with such setting (using checkboxes on Options & Components page) the new option has wrong configuration and such product couldn't be added to cart.
Solution
http://www.viart.com/downloads/admin_products_copy_properties-4.2.1.zip
Download the file above and extract 'admin_products_copy_properties.php' in the /admin folder of your shop replacing existing file. Please do not forget to make a backup copy of the current file in case something goes wrong.