Map caches stop generating when I am trying to build them

[EricHeinrichs]

We have a couple of maps that we have cached, and I am trying to add some a couple more levels at lower scales. But, when I try to generate the caches, it stops before it's done. The server logs don't tell me much:

Failed to get caching worker job result. ERROR 001444: Failed to submit caching worker job. ERROR 001444: Failed to submit caching worker job. Failed to execute (Manage Map Cache Tiles).

I have restarted it twice on the scales that we need, and it keeps stalling out. Does anyone know what the problem might be? 

[JayantaPoddar]

Restart the Caching Tools geoprocessing service running inside the System folder on the ArcGIS server Manager.