After 15 posts, we're finally getting to where we should've been from the first post. The RC=20 is indicative of a major failure.
The only things I can think of:
1. ISPF is not active or not available.
2. The macro is not being called from an ISPF EDIT/VIEW session.
Jeri Kattar, I think it's time for you to get in touch with your System Admin team and have them look into this issue. There isn't, and hasn't, been anything wrong with your code.