Handle "Unknown message" module:"botstack:fallback"

[cama]

Background...

fallback(message, senderID) {
log.debug("Unknown message", {
module: "botstack:fallback",
senderId: senderID,
message: message
});
//fb.reply(fb.textMessage("Ops, internal short circuit... Shutting
down... :("), senderID);* ----why does it happen that when this line is
active it loops constantly?*
};

This happens when Facebook sends messages that BotStackJS not yet able to handle correctly. Typically, this is a service message from facebook.