forest server does not seem to be set up correctly。也是花了很长时间都没解决，最后谷歌了一下，找到了一篇老外的帖子：
I had such a message, and I noticed also that the IP displayed when joining the server was not matching the IP I had on my host machine.Turns out, that writing the internal IP on the config file is not enough. It was automatically picking up another IP from a virtual network card (bug that ignores the config?).
So, in Windows, I disabled all network interfaces except the physical cabled one. From that point on I was able to connect.
1 - Double check what internal IP your server currently has.
2 - Make sure that the internal IP your server has is matching what is written on the server.cfg file.
3 - Make sure you have a manual/fixed IP on your server (otherwise it might change at some point in the future).
4 - In Windows (of the server), disable all other network interfaces (virtual or otherwise) apart from the one that has the desired IP.