Ssh is secure protocol andit tries to make everything properly to continue securely. There are a lot of different ssh security configuration. It one of them are violated ssh do not operates one of them is
Permissions 0777 for '/Users/username/.ssh/id_rsa' are too open.
It is recommended that your private key files are NOT accessible by others.
This private key will be ignored.
error. It is related with the permission of id_rsa file. If the permission is like 777 it will give this error and will not start. To correct this error the permission of the id_rsa file has to changed more secure level like 600.
root@ubu1:~# chmod 400 .ssh/id_rsa
root@ubu1:~# ls -al .ssh/id_rsa
-r-------- 1 root root 1675 Nov 2 16:33 .ssh/id_rsa