AWS EC2 Connection closed by when trying ssh into instance

Question

Recently I set up a new EC2 instance. The next day I was not able to connect to my instance via ssh. I could connect and disconnect the day before, I am sure I did nothing.

Answer 1

I had the same issue, Its the problem of the permissions you give to pem private key file. Make sure you run ssh command in the terminal with the sudo (Administrative) Access.