Remote SSH keys (ECDSA key) issue when accessing from client-side

[kkdao]

I have a Rockpro64 single board computer that I am trying to access remotely via an eMMC flashed Ubuntu iso image from here: https://www.armbian.com/rockpro64/, but keep getting the error message below. I was able to access the IP remotely from various laptops fine before by SSHing from the terminal, but after I failed at installing the program I wanted to install properly, I re-flashed the eMMC and have been getting this error ever since when accessing from other laptops (client-side) - I can SSH from the server-side fine with no issue FWIW.

@ 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 ECDSA key sent by the remote host is SHA256:IWefc//FoZcRXp...fpsF0eM. Please contact your system administrator. Add correct host key in C:\Users\User/.ssh/known_hosts to get rid of this message. Offending ECDSA key in C:\Users\User/.ssh/known_hosts:3 ECDSA host key for has changed and you have requested strict checking. Host key verification failed.

EDIT: I figured out I should be looking on my Windows laptop when I was expecting it to be on the Ubuntu server I was creating haha! Getting user@IP address: Permission denied (publickey) now though

Edited August 19, 2020 by kkdao

[martinayotte]

2 hours ago, kkdao said:

Offending ECDSA key in C:\Users\User/.ssh/known_hosts:3

You should edit this file and remove the offending line 3 ...