I updated my jenkins installation to the last version (1.533) and all the plugins have been updated.
I've got a problem with a project which must be cloned onto a slave (I just created the project, so this is the first time the repo is cloned).
When jenkins is trying to clone, an error is displayed:

Using strategy: Default
Using shallow clone
hudson.util.IOException2: remote file operation failed: /home/admin/jenkins/workspace/TESTLinux3 at hudson.remoting.Channel@69d99bff:Compilation Debian 6 64 bits
at hudson.FilePath.act(FilePath.java:912)
at hudson.FilePath.act(FilePath.java:889)
at hudson.plugins.git.GitSCM.determineRevisionToBuild(GitSCM.java:948)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1114)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1411)
at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:657)
at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:88)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:562)
at hudson.model.Run.execute(Run.java:1665)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:246)
Caused by: java.io.IOException: Remote call on Compilation Debian 6 64 bits failed
at hudson.remoting.Channel.call(Channel.java:723)
at hudson.FilePath.act(FilePath.java:905)
... 11 more
Caused by: java.lang.NoClassDefFoundError: Could not initialize class jenkins.model.Jenkins$MasterComputer
at hudson.FilePath.act(FilePath.java:916)
at hudson.FilePath.act(FilePath.java:889)
at org.jenkinsci.plugins.gitclient.Git.getClient(Git.java:65)
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:956)
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:948)
at hudson.FilePath$FileCallableWrapper.call(FilePath.java:2444)
at hudson.remoting.UserRequest.perform(UserRequest.java:118)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:326)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask$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)
Finished: FAILURE

When I looked at the code on github (GitSCM.java:948), the error seems to be located here:

public void buildEnvVars(AbstractBuild<?, ?> build, java.util.Map<String, String> env) {
super.buildEnvVars(build, env);
Revision rev = fixNull(getBuildData(build)).getLastBuiltRevision();
if (rev!=null) {
Branch branch = Iterables.getFirst(rev.getBranches(), null);
if (branch!=null) {
env.put(GIT_BRANCH, branch.getName());

String prevCommit = getLastBuiltCommitOfBranch(build, branch);
if (prevCommit != null)

{ env.put(GIT_PREVIOUS_COMMIT, prevCommit); }

}

env.put(GIT_COMMIT, fixEmpty(rev.getSha1String())); ###### <---- error located here (line 948)
}

But because I cloned for the first time, I shouldn't be here as far as I understand ?!?

Maybe the problem comes from another place ...