with artifactory-plugin 2.8.3 on artDocker.Push, i have thit new error

Agent successfully connected and online
Jan 13, 2017 7:34:36 AM org.jfrog.hudson.util.JenkinsBuildInfoLog info
INFO: Pushing image:<my_artifactory>/vscloud/demoapp:dev
channel stopped
Jan 13, 2017 7:34:41 AM org.littleshoot.proxy.impl.DefaultHttpProxyServer doStop
INFO: Shutting down proxy server immediately (non-graceful)
Jan 13, 2017 7:34:41 AM org.littleshoot.proxy.impl.DefaultHttpProxyServer closeAllChannels
INFO: Closing all channels (non-graceful)
Exception in thread "LittleProxy-JVM-shutdown-hook" java.lang.NoClassDefFoundError: io/netty/channel/group/ChannelMatchers
at io.netty.channel.group.DefaultChannelGroup.close(DefaultChannelGroup.java:225)
at org.littleshoot.proxy.impl.DefaultHttpProxyServer.closeAllChannels(DefaultHttpProxyServer.java:435)
at org.littleshoot.proxy.impl.DefaultHttpProxyServer.doStop(DefaultHttpProxyServer.java:403)
at org.littleshoot.proxy.impl.DefaultHttpProxyServer.abort(DefaultHttpProxyServer.java:385)
at org.littleshoot.proxy.impl.DefaultHttpProxyServer$1.run(DefaultHttpProxyServer.java:141)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: io.netty.channel.group.ChannelMatchers
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:149)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 6 more
Connection terminated

And on my Jobs:
I have this error:
java.lang.IllegalStateException: Build info capturing failed for docker image: <my_artifactory>/vscloud/demoapp:dev check build info proxy configuration.
at org.jfrog.hudson.pipeline.steps.DockerPushStep$Execution.run(DockerPushStep.java:106)
at org.jfrog.hudson.pipeline.steps.DockerPushStep$Execution.run(DockerPushStep.java:62)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)
at hudson.security.ACL.impersonate(ACL.java:260)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Finished: FAILURE