I want to send bulk SMS on WhatsApp without creating broadcast list. For that reason, I found pywhatsapp package in python but it requires WhatsApp client registration through yowsup-cli. So I've run yowsup-cli registration -r sms -C 00 -p 000000000000 which resulted in the error below: INFO:yowsup.common.http.warequest:{"status":"fail","reason":"old_version"} status: fail reason: old_version What did I do wrong and how can I resolve this? Continue reading...