Hi Vishal,
Glad that worked for you.
Regarding the encryption, it is very sensitive to any change in the environment. We use a number of environmental attributes like IP address, config location, username, and more to form the key. If any of those change, then the key is not valid to decrypt.
I've seen one situation in Windows where there was a job created to run the connector on a schedule. That job was using credentials that were in uppercase and it would create the key referencing an uppercase user name. Then, when the customer tried to run it from the command line, they were logged in using lower case and they would get decryption problems.
I suspect you're encountering something very similar. The log file in debug mode should show all of the values that it has used for consideration when encrypting the username/passwords and should show the same when decrypting. So any differences there should be observable, but again it could be something as basic as one single letter being uppercased when it should be lowercased.