Can't connect to slave after restart Jenkins

[Aneesh Sampath]

Hello,

I restarted Jenkins using "sudo service jenkins stop" and then "sudo service jenkins start".

In between the restart, I added my previously backed up JENKINS_HOME directory into the specified location of the JENKINS_HOME. 

When I started Jenkins, there is a red x icon on the slave node. In the slave node, I see instructions to launch the java application for connection. When I do that, however it brings the following error:

java.net.SocketException: Connection reset

at java.netSocketInputStream.read(Unknown Source)

at java.ioBufferedinputStream.fill(Unknown Source)

"" .read(Unknown Source)

at hudson.remoting.ChannelBuilder.negotiate(ChannelBuilder.java:331)

at hudson.remoting.ChannelBuilder.build(ChannelBuilder.java.282)

at hudson.remoting.Engine.run(Engine.java.272)

Could there have been a change when I restarted? The new loaded JENKINS_HOME directory was identical to how it was previously. I was just testing a backup. 

Thanks