I have faced this error when I was trying to setup a remote script execution via SSH, on my CentOS box. Initially I have made sure that the user as which I run the particular script can access the particular file about which it complaints it cannot read. But permission looks fine. After a quick googling, I could fix it by adding the remote host hey to the known_hosts file of the local user I try ( simple try “ssh remoteuser@remoteIP” as local user ) and then I was able to run the remote script via SSH fine.