Idahowalker:
What have you done to troubleshoot the error?
Well I first thought that "moveTo(messageTemp)" is being received as a string (String&)' so I created a function node to make sure the MQTT was sent as a number, with no effect.
Then I googled the whole error, this was the best response but a bit long winded with using an array which I didn't need.
https://forum.arduino.cc/index.php?topic=334231.0
I then googled Arduino function and came to the conclusion that something else hasn't been declared, but I can't see what I'm afraid.