A message that is normally caught by CA Opera and generates an action (such as a WTO) did not trigger any action.
CA Opera Release 3.1
Probable cause is buffer full.
1) Apply APAR LO04578 if you do not already have this.
2) If you have fewer than 12 Action Processors specified in ACTPROCS, then increase to 12.
3) Adjust the rules to be more efficient so that they conserve Action Processors. For example, only generate a WTO for the first message in a series.
You can specify more than 12 Action Processors, but you will not get any more than 12.