Jenkins nœud de problèmes de connexion

Salut j'ai obtenu l'erreur suivante mais mon nœud est dans jenkins journaux, tout est ok, mais sur certains de mes travaux qui vont sur les noeuds, j'ai eu la suite de la difficulté à

12:59:29 [EnvInject] - Loading node environment variables.
12:59:29 ERROR: SEVERE ERROR occurs
12:59:29 org.jenkinsci.lib.envinject.EnvInjectException: hudson.remoting.ChannelClosedException: channel is    already closed
12:59:29    at org.jenkinsci.plugins.envinject.service.EnvironmentVariablesNodeLoader.gatherEnvironmentVariablesNode(EnvironmentVariablesNodeLoader.java:75)
12:59:29    at org.jenkinsci.plugins.envinject.EnvInjectListener.loadEnvironmentVariablesNode(EnvInjectListener.java:81)
12:59:29    at org.jenkinsci.plugins.envinject.EnvInjectListener.setUpEnvironment(EnvInjectListener.java:39)
12:59:29    at hudson.model.AbstractBuild$AbstractBuildExecution.createLauncher(AbstractBuild.java:637)
12:59:29    at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:543)
12:59:29    at hudson.model.Run.execute(Run.java:1676)
12:59:29    at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
12:59:29    at hudson.model.ResourceController.execute(ResourceController.java:88)
12:59:29    at hudson.model.Executor.run(Executor.java:231)
12:59:29 Caused by: hudson.remoting.ChannelClosedException: channel is already closed
12:59:29    at hudson.remoting.Channel.send(Channel.java:524)
12:59:29    at hudson.remoting.Request.call(Request.java:129)
12:59:29    at hudson.remoting.Channel.call(Channel.java:722)
12:59:29    at hudson.FilePath.act(FilePath.java:1003)
12:59:29    at org.jenkinsci.plugins.envinject.service.EnvironmentVariablesNodeLoader.gatherEnvironmentVariablesNode(EnvironmentVariablesNodeLoader.java:44)
 12:59:29   ... 8 more
12:59:29 Caused by: java.io.IOException
12:59:29    at hudson.remoting.Channel.close(Channel.java:1007)
12:59:29    at hudson.slaves.ChannelPinger$1.onDead(ChannelPinger.java:110)
12:59:29    at hudson.remoting.PingThread.ping(PingThread.java:120)
12:59:29    at hudson.remoting.PingThread.run(PingThread.java:81)
12:59:29 Caused by: java.util.concurrent.TimeoutException: Ping started on 1401694124050 hasn't completed at 1401694364050
12:59:29    ... 2 more
12:59:29 Archiving artifacts
12:59:29 Email was triggered for: Failure
12:59:29 Sending email for trigger: Failure
12:59:29 ERROR: Error: No workspace found!
12:59:29 Error retrieving environment vars: channel is already closed
12:59:29 Sending email to: $EMAIL_USERS
12:59:49 Error sending to the following INVALID addresses: $EMAIL_USERS
12:59:49 [EnvInject] - [ERROR] - SEVERE ERROR occurs: channel is already closed

 12:59:49 Finished: FAILURE