@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the RSA key sent by the remote host is fa:71:5e:f7:5f:4f:72:c6:15:2e:58:f6:8b:4e:b0:96. Please contact your system administrator. Add correct host key in /Users/goliatone/.ssh/known_hosts to get rid of this message. Offending RSA key in /Users/goliatone/.ssh/known_hosts:45 RSA host key for 192.168.1.134 has changed and you have requested strict checking. Host key verification failed.

ssh-keygen -R <host>

If google sent you here, while looking for an answer as to why you suddenly can't access your vagrant box, this answer will help the most. When starting up a new and different vagrant box, that box may generate a new rsa-key that will be different from the previously registered rsa-key for that same local host. If this is this case, you can trust that the change is only a nuisance, and you can remove the old invalid key –

Make sure you know what you are doing!