The error is associated with MySQL directly.
Unable to connect to any of the specified MySQL hosts could mean a few things. You’ve either: Installed MySQL server incorrectly, did not specify correct convars or specified wrong username/password in the convar located in server.cfg. Check your server.cfg and make sure your host, username and password is correct. Make sure you are also loading all of the needed resources in the recommended order.
If that does not work, then you may be using the latest EssentialMode5.x, which I believe doesn’t support MySQL by the looks of it? https://goo.gl/rVqkBN
Someone correct me if I am wrong anyways