We were in middle of a Spool upgrade, from V12 to v14, and after bringing up the task, we started receiving ESF005 and ESF018 messages.
Release : 14.0
In production, the client was running from a back-leveled library, as the Spool 14.0 load library was further down in their linklist.
The problem was originally resolved by having the client place the load library in a //STEPLIB in the Spool proc.
The client then placed the load library in a proper position in the linklist, removed the //STEPLIB reference, and they were then able to get the proc to successfully run.