How to avoid Job Scheduler shutdown unexpectably

The child pipeline got failed before preparing the pipeline because scheduler got shutdown unexpectedly so it’s not getting the required resources to run the job
Reason: java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@98307e7 rejected from java.util.concurrent.ScheduledThreadPoolExecutor@21ea402c[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 1]

How to avoid this kind of issues?

Without some more details it’s hard to say, but I would guess the parent pipeline failed in some way and that resulted in the children being terminated.