Elementis

Found a solution that work with WPML. In plugins/simplemap/classes/simplemap.php, I changed

wp_enqueue_script( 'simplemap-master-js', site_url() . '?simplemap-master-js=1&smpid=' . $post->ID, array( 'jquery' ) );

by

wp_enqueue_script( 'simplemap-master-js', site_url() . '/'.ICL_LANGUAGE_CODE. '/?simplemap-master-js', array( 'jquery' ) );