When I am running a matrix job, after all the children pass the build successfully, the parent slave suddenly fails at the end of the build.

This happens sometimes, and a reboot always helps to solve the problem, but after some time, it happens again, and we need to reboot the parent slave again.

• it happens only on parent slave in matrix jobs.
• Lately, we changed the JVM options Maximum Heap size to 7GB when connecting the parent as Jenkins slave, it didn't help either.

This is the error it produces:
FATAL: Remote call on parent_slave failed
Also: hudson.remoting.Channel$CallSiteStackTrace: Remote call to parent_slave
at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1741)
at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
at hudson.remoting.Channel.call(Channel.java:955)
at hudson.Launcher$RemoteLauncher.kill(Launcher.java:1086)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:510)
at hudson.model.Run.execute(Run.java:1853)
at hudson.matrix.MatrixBuild.run(MatrixBuild.java:323)
at hudson.model.ResourceController.execute(ResourceController.java:97)
at hudson.model.Executor.run(Executor.java:427)
java.lang.NoClassDefFoundError: Could not initialize class hudson.slaves.SlaveComputer
at hudson.util.ProcessTree.get(ProcessTree.java:432)
at hudson.Launcher$RemoteLauncher$KillTask.call(Launcher.java:1103)
at hudson.Launcher$RemoteLauncher$KillTask.call(Launcher.java:1094)
at hudson.remoting.UserRequest.perform(UserRequest.java:211)
at hudson.remoting.UserRequest.perform(UserRequest.java:54)
at hudson.remoting.Request$2.run(Request.java:369)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused: java.io.IOException: Remote call on parent_slave failed
at hudson.remoting.Channel.call(Channel.java:961)
at hudson.Launcher$RemoteLauncher.kill(Launcher.java:1086)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:510)
at hudson.model.Run.execute(Run.java:1853)
at hudson.matrix.MatrixBuild.run(MatrixBuild.java:323)
at hudson.model.ResourceController.execute(ResourceController.java:97)
at hudson.model.Executor.run(Executor.java:427)