Bobclass does not send WhatsApp messages itself. It opens the WhatsApp app on your device with the message and the recipient already filled in, and you send it from there. So when WhatsApp messaging misbehaves, the cause is usually on the device or on the client's phone number.
Check these three in order.
WhatsApp has to be installed and properly set up on the device you are using Bobclass on. If you have Bobclass on both an iPad and a phone, WhatsApp needs to be working on whichever one you are sending from.
This is the most common cause. The number on the client's profile must be a mobile number, and it is far more reliable with the international country code included.
Write it as , not 666777888.
Open the client in and check their number. If you use WhatsApp as your regular channel, it is worth going through your list once and adding country codes everywhere.
On some devices, if the WhatsApp app has not been used for a while, the system suspends it in the background. When Bobclass calls it, it may not respond immediately.
Open WhatsApp by hand once, then try again from Bobclass.
If WhatsApp is not working for you, you can send by email or SMS instead. The channel is set per device in — see Messaging channels .