The S878/U878 error occurred because the task ran out of storage.
It was recommended that the client use REGION=256M in their Deliver RMOSTC task.
When a Deliver RMOSTC task comes down due to a problem:
. Start the RMOSTC task with "/S rmostc,PARM=OFF", which will start the task, removing the hooks, then bring it down properly.
. Start the task with "/S rmostc".