RSA host key for 188.166.XXX.XXX has changed and you have requested strict checking.
Host key verification failed.

So, I’v rebuild a droplet on DigitalOcean, and logically, when I tried to ssh it, SSH Keys were different…. Easy so solve it…

On a Mac OSX, on console, lets change to root

sudo bash

Lets edit known_hosts

nano /Users/YOUR_USERNAME/.ssh/known_hosts

Remove the entry of the respective host/ip.
Save and exit nano, exit root.. and ssh it! 🙂