AWS destination setting

I am testing AWS connection but its giving me

"Sending file to: Bucket: Directory: Unknown: errno:8 Undefined index: Message /home/expiria/ftp/html/wp-content/plugins/snapshot/lib/Snapshot/Model/Destination/aws/index.php on line 363"

I have also tried it with fresh access key and secret key of AWS. But that does not seem to help.

It keeps showing "Destination: 1 Fail".

Please help.