After activation of the File Leak Detector Plugin via the 'activate' button, the Jenkins CLI stops working:

$ java -jar jenkins-cli.jar -s http://myjenkins:8080 help
Exception in thread "main" java.lang.reflect.UndeclaredThrowableException
at $Proxy2.main(Unknown Source)
at hudson.cli.CLI.execute(CLI.java:322)
at hudson.cli.CLI._main(CLI.java:468)
at hudson.cli.CLI.main(CLI.java:373)
Caused by: java.io.IOException: Remote call on CLI connection to http://myjenkins:8080 failed
at hudson.remoting.Channel.call(Channel.java:673)
at hudson.remoting.RemoteInvocationHandler.invoke(RemoteInvocationHandler.java:158)
... 4 more
Caused by: java.lang.IllegalAccessError: org/kohsuke/args4j/CmdLineParser$1
at org.kohsuke.args4j.CmdLineParser.<init>(CmdLineParser.java:94)
at hudson.cli.CLICommand.main(CLICommand.java:211)
at hudson.cli.CliManagerImpl.main(CliManagerImpl.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at hudson.remoting.RemoteInvocationHandler$RPCRequest.perform(RemoteInvocationHandler.java:275)
at hudson.remoting.RemoteInvocationHandler$RPCRequest.call(RemoteInvocationHandler.java:256)
at hudson.remoting.RemoteInvocationHandler$RPCRequest.call(RemoteInvocationHandler.java:215)
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 hudson.cli.CliManagerImpl$1.call(CliManagerImpl.java:63)
at hudson.remoting.InterceptingExecutorService$2.call(InterceptingExecutorService.java:95)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

The corresponding line in args4j::CmdLineParser.java is

Collections.sort(options, new Comparator<OptionHandler>() {
public int compare(OptionHandler o1, OptionHandler o2)

});

Please have a look - the plugin is really useful, but the CLI is essential.

PS
I tried to file this issue against the 'file-leak-detector' component, but that doesn't exist. Please forward as appropriate.