Known issue

Problem:
The client is experiencing unresolved issues with their WordPress site using WPML, specifically related to 404 errors when translating product brand slugs.
Solution:
If you're experiencing similar issues, we recommend trying the following workaround: Navigate to Settings > Permalinks in your WordPress dashboard, and manually set a static value for the brand slug. Initially, 'brand' will appear as a placeholder slug. To use 'brand' as a manually set slug, you must edit the field, type the value, and save it. This solution is based on a known issue which can be further explored here: Translating Product Brand Slug Can Lead to 404s.

Please note that this solution might be outdated or not applicable to your specific case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the issue persists, please open a new support ticket at WPML support forum for further assistance.

Problem:
The client is experiencing an issue where email notifications sent from their multilingual e-commerce sites viviscal.bg and viviscal-store.com are displaying in multiple languages instead of just the language in which the order was made. This problem is linked to the YAY Mail plugin's handling of languages.
Solution:
We recommend updating the YAY Mail plugin's code to ensure that emails are sent in the correct language. Specifically, modify the

get_site_language

function in the WPMLIntegration.php file. Here's the step-by-step guide:

1. Backup the original WPMLIntegration.php file located in /wp-content/plugins/yaymail-pro/includes/Integrations/Translations/.
2. Replace the existing

   get_site_language

   function with the following code:

   public static function get_site_language( $order ) {
           global $sitepress;
           $language = \defined( 'ICL_LANGUAGE_CODE' ) ? ICL_LANGUAGE_CODE : 'en';
           if ( null !== $order || isset( $GLOBALS['yaymail_set_order'] ) ) {
               $order_data = ( null !== $order ) ? $order : $GLOBALS['yaymail_set_order'];
               // $order_language = $order_data->get_meta( 'wpml_language' );
               $post_language_details = apply_filters( 'wpml_post_language_details', null, $order_data->get_id() );
               $order_language        = isset( $post_language_details['language_code'] ) ? $post_language_details['language_code'] : '';
               if ( ! empty( $order_language ) ) {
                   $language = $order_language;
               }
           }
           $sitepress->switch_lang( $language );
           return $language;
       }

   with

   public static function get_site_language( $order ) {
       global $sitepress;
    
       // Use default language as safe fallback
       $language = apply_filters( 'wpml_default_language', null );
    
       if ( null !== $order || isset( $GLOBALS['yaymail_set_order'] ) ) {
           $order_data = ( null !== $order ) ? $order : $GLOBALS['yaymail_set_order'];
    
           $order_language = $order_data->get_meta( 'wpml_language', true );
    
           if ( ! empty( $order_language ) ) {
               $language = $order_language;
           }
       }
    
       do_action( 'wpml_switch_language', $language );
       return $language;
   }

3. After updating the code, test the email notifications to ensure they are now sent in the correct language.

If this solution does not resolve your issue or seems irrelevant due to updates or different configurations, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the problem persists, please open a new support ticket.