hudson.util.IOException2: Slave JVM has not reported exit code. Is it still running?
	at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:953)
	at hudson.plugins.sshslaves.SSHLauncher.access$400(SSHLauncher.java:133)
	at hudson.plugins.sshslaves.SSHLauncher$2.call(SSHLauncher.java:711)
	at hudson.plugins.sshslaves.SSHLauncher$2.call(SSHLauncher.java:696)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Remote call on trusted-agent-1 failed
	at hudson.remoting.Channel.call(Channel.java:789)
	at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:508)
	at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:381)
	at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:945)
	... 7 more
Caused by: java.lang.ClassFormatError: Failed to load hudson.slaves.SlaveComputer$SlaveVersion
	at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:340)
	at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:251)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:249)
	at hudson.remoting.MultiClassLoaderSerializer$Input.resolveClass(MultiClassLoaderSerializer.java:114)
	at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1589)
	at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1494)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1748)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349)
	at hudson.remoting.UserRequest.deserialize(UserRequest.java:184)
	at hudson.remoting.UserRequest.perform(UserRequest.java:98)
	at hudson.remoting.UserRequest.perform(UserRequest.java:48)
	at hudson.remoting.Request$2.run(Request.java:326)
	at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
	at java.lang.Thread.run(Thread.java:662)
	at ......remote call to trusted-agent-1(Native Method)
	at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1416)
	at hudson.remoting.UserResponse.retrieve(UserRequest.java:220)
	at hudson.remoting.Channel.call(Channel.java:781)
	... 10 more
Caused by: java.lang.UnsupportedClassVersionError: hudson/slaves/SlaveComputer$SlaveVersion : Unsupported major.minor version 51.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
	at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:338)
	at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:251)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:249)
	at hudson.remoting.MultiClassLoaderSerializer$Input.resolveClass(MultiClassLoaderSerializer.java:114)
	at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1589)
	at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1494)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1748)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349)
	at hudson.remoting.UserRequest.deserialize(UserRequest.java:184)
	at hudson.remoting.UserRequest.perform(UserRequest.java:98)
	at hudson.remoting.UserRequest.perform(UserRequest.java:48)
	at hudson.remoting.Request$2.run(Request.java:326)
	at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
	at java.lang.Thread.run(Thread.java:662)
[04/19/16 05:12:30] Launch failed - cleaning up connection
[04/19/16 05:12:30] [SSH] Connection closed.
ERROR: Connection terminated
java.io.IOException: Unexpected termination of the channel
	at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:50)
Caused by: java.io.EOFException
	at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2332)
	at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2801)
	at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:801)
	at java.io.ObjectInputStream.<init>(ObjectInputStream.java:299)
	at hudson.remoting.ObjectInputStreamEx.<init>(ObjectInputStreamEx.java:48)
	at hudson.remoting.AbstractSynchronousByteArrayCommandTransport.read(AbstractSynchronousByteArrayCommandTransport.java:34)
	at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:48)