The problem is that SSH client application on your Mac has saved previous remote system identification for this IP address. Simple solution for you is to delete the known_hosts file in /Users/Dee/.ssh/known_hosts (or open it in text editor and remove line 6).
Offending ECDSA key in /Users/Dee/.ssh/known_hosts:
how do I delete it? This is new territory for me. Hope u can help.