#77380 by hunmonk, fix the content type delete button.

modules/node/content_types.inc

@@ -272,7 +272,7 @@ function node_type_form_submit($form_id, $form_values) {
     node_type_reset($type);
   }
   elseif ($op == t('Delete content type')) {
-    return 'admin/content/types/'. $type->old_type .'/delete';
+    return 'admin/content/types/'. str_replace('_', '-', $type->old_type) .'/delete';
   }
 
   if (!empty($form_values['old_type'])) {