Fixing “WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!” and “IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!”

The best way to pay for a lovely moment is to enjoy it.

For people who work with AWS instances, if you tried to reuse your keyfile on a new instance, after login into your instance, you will see a warning such as:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ 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 ED25519 key sent by the remote host is
SHA256:d+HvnUmSPGsyxwYrDQiAKeEpBX38pkYVxRv9wezIpeE.
Please contact your system administrator.
Add correct host key in /Users/home/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/home/.ssh/known_hosts:75
Host key for mytrip.chat has changed and you have requested strict checking.
Host key verification failed.

A quick fix for this is to run this command

ssh-keygen -R hostname

Note: replace hostname with your domain name or iP addresss

You get something like this

/Users/home/.ssh/known_hosts updated.
Original contents retained as /Users/home/.ssh/known_hosts.old

Redo your login command and you are good to go!