If you cannot change a group in the group management in Ziber Team, there can be two reasons for this.
When your educational institution keeps the student data in Ziber Team up-to-date via the Student Administration System (LAS), the group division of the school is also included. We call these groups "IMPORT groups" and cannot be changed in Ziber Team. You can only change these groups (name, students and school team members) in the LAS, after which they will be updated in Ziber Team.
not classified in manual group
The other reason you wouldn't be able to edit a group is because you are not assigned to a "manual group" as a school team member. So only school team members who are assigned to a group can also change the content of that group. Ask your colleague if you still want to change a certain group!