"cannot create deliverable item" message on edit on deliverable view

https://nbm-staging.nuxeo.io/nuxeo/app/#/deliverable//apricot/ProjectContainer/January%20Campaign%20-%202018/DeliverableContainer/new%20deliverable%20type

when editing the deliverable item from this view (as the project manager, Michele), clicking "create" gives an error message stating that the item cannot be created. This happens on all browsers.

the item CAN be edited as expected from the project view.