Labirynth has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.
If you are trying to send this message to multiple recipients, remove Labirynth from the recipient list and send the message again.
Unfortunately I can't send you the set via Private message, perhaps we can arrange another method of transferring the set, or you can change your profile options and allow private messages.