While deleting a few thousand jobs, eventually the background task stopped with this error (ver 8.0.17.1 ):

An unexpected error occurred while Deleting Job(s):
Sandbox process exited unexpectedly while waiting for response from Event. (Deadline.Plugins.PluginException)
   at Deadline.Events.SandboxedEventManager.a(DeadlineMessage A_0)
   at Deadline.Events.SandboxedEventManager.OnJobsDeleted(Job[] jobs, DataController dataController)
   at Deadline.Controllers.DataController.DeleteJobAndAuxiliaryFiles(Job job)
   at Deadline.Monitor.WorkItems.DeleteJobsWI.InternalDoWork()
   at Deadline.Monitor.MonitorWorkItem.DoWork()

Do you have an OnJobsDeleted() that could possibly block for a long time? I don’t know if we’ve implemented any sort of keep-alive over the versions but I can find out. My guess at the moment is that the event ran into some sort of timeout while calling the OJD event for a particular job.