Ec2 Market place Linux Instance Permission denied (publickey) - amazon-web-services

Question

I have a Wowza instance purchased from Marketplace, about 4 hrs ago I was able to connect it and was doing some operations on it. But now when I am trying to connect it gives Permission denied (publickey) error. I used chmod command to give 777 permissions on ./ And here is the real cause I think.
From this solution when I am trying to attach the root volume of this instance to other instance of same type it is giving the same error, but when voulme is detached it is being connected successfully. The volume of marketplace instance can be attached to similar type of instance only.
Now how can I change the permission of that .ssh directory? Can you please help me out.
Here are the logs when I am trying to connect with the instance:
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 54.69.133.11 [54.69.133.11] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file Desktop/Shivam/mypemfile.pem type -1
debug1: identity file Desktop/Shivam/mypemfile.pem-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5-etm#openssh.com none
debug1: kex: client->server aes128-ctr hmac-md5-etm#openssh.com none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 6a:48:f5:14:13:9a:a1:79:e8:44:bb:0d:6b:8d:b7:59
The authenticity of host '54.69.133.11 (54.69.133.11)' can't be established.
ECDSA key fingerprint is 6a:48:f5:14:13:9a:a1:79:e8:44:bb:0d:6b:8d:b7:59.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '54.69.133.11' (ECDSA) to the list of known hosts.
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: Desktop/Shivam/mypemfile.pem
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).

Answer 1

Products launched from the AWS Marketplace have restrictions that non-marketplace instances don't have mainly to enforce licensing. You have run into one of the restrictions.
Here is a relevant thread on the AWS Forums that may be of use, especially the final post in the thread:
If a volume has an AWS Marketplace product code:
The volume can only be attached to a stopped instance.
You must be subscribed to the AWS Marketplace code that is on the volume.
The configuration (instance type, operating system) of the instance must support that specific AWS Marketplace code. For example, you
cannot take a volume from a Windows instance and attach it to a Linux
instance.
AWS Marketplace product codes are copied from the volume to the instance.

Answer 2

I did not check, but you can try this trick.
You can specify user data to configure an instance or run a configuration script during launch.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html#user-data-shell-scripts
When you create a new instance
Choose AMI from Market Place
Choose Instance Type
Configure Instance -> Advanced Details -> Used data.
Put here you bash script to change permissions back.
Add Storage
Change root device or add a new one from the snapshot of your EBS.
Tag Instance
Configure Security Group
Review and Launch