SFTP - Could not determine the type of file

Error:

As we have SFTP polling for a file we got the below issue while executing. When we execute for the first time we are getting this issue, after this the SFTP is getting blocked. When we checked the SFTP Server logs , Adeptia is trying to connect the Server for each second and final after 15 attempts the Server is getting blocked. We have given the correct credentials to the polling activity and placed the file in the SFTP location.

Error:
Error in execution for activity FtpPollingService:PollingFtp_pollReadyFile:192168122001136386071251900672[com.adeptia.indigo.utils.IndigoException: Unknown message with code ""Could not determine the type of fi]

Cause:

The Secured FTP connector is incorrect

Resolution:

Change the Secured FTP connector under Adv. Properties to "J2SSH" instead of using "J2SCH(VFS)"