What is "Found a server, but the address may be out of date"?
When you click "Find server and connect" button, lackey downloads the IP of the server from lackeyccg.com, and then it caches it, and then connects to that IP. If the website is down, for lackey can't retrieve the server IP for some reason, Lackey will attempt to use the previous address (from the cache). That's what that message meant. Maybe the website was down or something.