Reservation not generated from Pull List MF60 in S4 Hana

Hi Experts,

I am working on S4 Hana. I have done necessary configuration for Pull list. Upon seeing the component requirements, I intend to generate reservation, so that parts can be ordered from warehouse. However, once I click on "Replenishment Proposals" button, system does not generate any reservation. It stays on the same page. Also, the save button is not active on the pull list. I am using PP-PI. I am sure pull list can be used for PP-PI as well.

Any expert advise on what's going wrong?