Invalid/unknown SSL header was received from peer during SSL handshake.>

This is the exception that we got, when we were trying to start one of our server in cluster. The managed server to be started is on machine1 and cluster is on different machine2. We changed the communication type to plain in the console under nodemager settings for the machine2. But still the issue was same.The server was still using SSL for communication, since the last line of the log after nodemanager start/restart, was still "secure socket listener started on port 5556".

It got resolved by changing the SecureListener to false in the nodemanager.properties file, which made the nodemanager to use Plain communication. This changed the last line in nodemanager log after restating to
Plain socket listener started on port 5556.