Can I schedule a committed cost report?

SUGGESTED

I'd like to schedule a weekly email for 21 - Committed Costs report, but the schedule button is grayed out. However, that button becomes available if i selects 51 - Committed Costs~Developer. I'm wondering why report 51 can be scheduled but 21 cannot as 21 is the one I really want to use.

Thank you.

Boyang Wang