Are you still using those very old Job Control standard options / options in your z/VSE job streams ?
Ingolf24 120000DRN3 Visits (2929)
I just noticed that we did not describe a change we made with z/VSE 5.1, because we weren't aware, that anyone is still using those very old Job Control options. We just got a customer PMR, where they had Job Control errors after they migrated to z/VSE 5.1. In between many of our customers are on z/VSE Version 5. This was the first issue, we noticed.