"Warning: Invalid argument" vermeiden bei nichtdefinierter custom taxonomy

//* Single: EXIF Map
add_action('genesis_entry_footer', 'wp_exifmap_after_autor', 60);
function wp_exifmap_after_autor() {
if (is_single() ) {


if (function_exists('z_taxonomy_image'))
foreach (get_the_terms(get_the_ID(), 'estado') as $cat) :; 


echo "<h3><i class='fa fa-map-o' aria-hidden='true'></i> "; 
_e('Landkarten von ','eleven40');
echo $cat->name;
_e(' und der Region:','eleven40');
echo "</h3>";


echo "<a href='";
echo get_term_link($cat->term_id, 'estado');
 echo"'>";
 echo"<img src='";
 echo z_taxonomy_image_url($cat->term_id);
 echo"' class='exifmap' title='";
 echo $cat->name;
 echo"' alt='";
 echo $cat->name;
 echo"'/></a>";