When adding product to cart, the page reloads to current product, but does not load okay.
Server Logs:
[] operator not supported for strings in /httpdocs/wp-content/plugins/woocommerce-product-addon/templates/render-fields.php:89
It seems you are declaring $default_value as a string here:
Line 54:
$default_value = ( isset($meta['default_value'] ) ? $meta['default_value'] : '');
Then later on, try to push values to array $default_values…. this cannot be done
Line 89:
$default_value[] = json_decode( stripslashes($data), true);