HLLX STC Displays from a REXX (e.g.)

Hi all,

I've a doubt ... I remember, when I migrated V7R1M3C to V8R1M0A at some client, that the displays at HLLX REXX worked just fine ... I mean I'd a rexx with Say "Hello World" at some point and when it was triggerd this message appeard at HLLX STC.

Now ... Today I'm with a V8R1M4 migration, in another client, and the same situation doen't work ... why? Have I forgot something or something else is needed. I can't see any display at all ... Only when I force an ABEND ... In this case I get the messages and correspondent HLLX STC ABEND ...