After installing the Jenkins plugin file-leak-detector version 1.6, I am not able to run the plugin on my Jenkins server.

Plugin: https://plugins.jenkins.io/file-leak-detector

Repro Steps:

1. Install the Cloudbees File Leak Detector on the Jenkins server via Jenkins > Manage Jenkins > Manage Plugins > Available > Cloudbees File Leak Detector
2. Go to Jenkins > Manage Jenkins > Open File Handles
   1. This opens the URL https://<jenkins-url>/file-handles/
3. I click "activate" on the page here with no arguments:
   1. 
4. That takes me to this page with an error and stacktrace:
   1. https://<jenkins-url>/file-handles/activate
   2. 

   3. java.lang.Error: Failed to activate file leak detector.
      Perhaps wrong parameters.
      See logs for more info.
      Specifically, look for 'Agent failed to start!' or something related
      
      
      	at com.cloudbees.jenkins.plugins.file_leak_detector.FileHandleDump.doActivate(FileHandleDump.java:100)
      	at java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:627)
      	at org.kohsuke.stapler.Function$MethodFunction.invoke(Function.java:396)
      	at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:408)
      	at org.kohsuke.stapler.interceptor.RequirePOST$Processor.invoke(RequirePOST.java:77)
      	at org.kohsuke.stapler.PreInvokeInterceptedFunction.invoke(PreInvokeInterceptedFunction.java:26)
      	at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:212)
      	at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:145)
      	at org.kohsuke.stapler.MetaClass$11.doDispatch(MetaClass.java:537)
      	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:58)
      	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:739)
      Caused: javax.servlet.ServletException
      	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:789)
      	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:870)
      	at org.kohsuke.stapler.MetaClass$9.dispatch(MetaClass.java:458)
      	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:739)
      	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:870)
      	at org.kohsuke.stapler.Stapler.invoke(Stapler.java:668)
      	at org.kohsuke.stapler.Stapler.service(Stapler.java:238)
      	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
      	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1655)
      	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:154)
      	at org.jenkinsci.plugins.ssegateway.Endpoint$SSEListenChannelFilter.doFilter(Endpoint.java:243)
      	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)
      	at io.jenkins.blueocean.ResourceCacheControl.doFilter(ResourceCacheControl.java:134)
      	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)
      	at io.jenkins.blueocean.auth.jwt.impl.JwtAuthenticationFilter.doFilter(JwtAuthenticationFilter.java:61)
      	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)
      	at jenkins.telemetry.impl.UserLanguages$AcceptLanguageFilter.doFilter(UserLanguages.java:128)
      	at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:151)
      	at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:157)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:99)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
      	at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at jenkins.security.BasicHeaderProcessor.doFilter(BasicHeaderProcessor.java:93)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
      	at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
      	at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
      	at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:90)
      	at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:82)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
      	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
      	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
      	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
      	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
      	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
      	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
      	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
      	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
      	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1340)
      	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
      	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
      	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
      	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
      	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1242)
      	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
      	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
      	at org.eclipse.jetty.server.Server.handle(Server.java:503)
      	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:364)
      	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
      	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
      	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
      	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
      	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
      	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
      	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
      	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
      	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
      	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
      	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
      	at java.lang.Thread.run(Thread.java:748)