You might have come across this error when using SSH. This is as a result of the IP address of the remote host you're trying to SSH into having changed since the last login. To solve this you have to remove the conflicting entry in ~/.ssh/known_hosts. Run the following commands
nano ~/.ssh/known_hosts
Go to the line where the conflicting SSH entry is listed and press:
CTRL + k
Next, save the file by pressing:
CTRL + o
Finally exit the file by pressing:
CTRL + x
You will now be able to SSH into the remote box as per normal.