can't create 'home/Username/.ssh' directory

I was trying to connect to amazon ec2 server through ssh. Problem is when i try to connect to the server through ssh i get error. The command i am using is ssh -i file.pem ec2-user@11.11.11.11 (This is just an example of command). The error i get is

can't create 'home/Username/.ssh' directory. The authenticity of host '11.11.11.11' can't be established. RSA key fingerprint is 11:11:11:11:11:11:11:11:11:11:11:11:11:11:11:11. Are you sure you want to continue connecting (yes/no)? yes Failed to add the host to the list of known hosts (/home/Username/.ssh/known_hosts).

I found a solution from this link couldn't properly understand the solution.

Link ->http://ift.tt/1MiRK3e

Please help me configuring the file according the solution given above.