Ticket #22704: 22704.9.diff

src/wp-admin/includes/misc.php

@@ -296 +296 @@
  */
 function show_message($message) {
         if ( is_wp_error($message) ){
-                if ( $message->get_error_data() && is_string( $message->get_error_data() ) )
-                        $message = $message->get_error_message() . ': ' . $message->get_error_data();
+                if ( $message->get_error_data() )
+                        $message = $message->get_error_message() . ': ' . implode( ", ", (array) $message->get_error_data() );
                 else
                         $message = $message->get_error_message();
         }