Ticket #21543: 21543.3.diff

src/wp-admin/edit-form-advanced.php

@@ -157 +157 @@
         else
                 $tax_meta_box_id = $tax_name . 'div';
 
-        add_meta_box( $tax_meta_box_id, $label, $taxonomy->meta_box_cb, null, 'side', 'core', array( 'taxonomy' => $tax_name ) );
+        if ( false !== $taxonomy->meta_box_cb )
+                add_meta_box( $tax_meta_box_id, $label, $taxonomy->meta_box_cb, null, 'side', 'core', array( 'taxonomy' => $tax_name ) );
 }
 
 if ( post_type_supports($post_type, 'page-attributes') )