The certificate used to sign the message was issued by a certificate authority whose own certificate has been revoked. You should not trust the validity of this message until you verify its contents with the sender.
Le certificato usate pro firmar le message ha essite publicate per un certificato autoritate del que proprie certificato ha essite revocate. Tu deberea non acceptar le validitate de tal message usque tu verifica su contentos con le expeditor.