Francisco, I think you got the same type of errors couple of years back also. 

This error is most often due to the TCP connection going away without the adaptor realizing it.  If the problem is a network issue, the error may go away once that's resolved.  If StayConnected is set to a large value (or -1), it may also help to set it to a small, positive value (such as 5 or 10).  This value controls how many seconds of idle time the adaptor allows.  If it's currently higher than one of the TCP timeouts in your connection, that could account for the error.

Hello Francisco,

in the  configuration settings in SSL configurations can you try !SFTP