Steps to reproduce:
create a work group with 2 users Mary and Peter; Mary is the group manager
create a patient record and set the group to be the owner of the record
login either as Mary and Peter
try to make any change (add/remove collaborator; make record public, etc)
Sometimes an error msg shows up. See the attached screenshot.
Observed in the family record form as well.
This problem does not exist in version 1.3.7.
In 1.4RC1 I was able to modify permissions via REST API.