Login as admin. Create cohorts and add users to it https://docs.moodle.org/30/en/Cohorts . And add a new role (i.e. Parent role ). Go to Site administration ► Users ► Permissions ► Assign user roles for entire cohort. Without entering anything, click Assign . Confirm that there is no PHP warning message shown. Confirm that a notification message is shown: No cohort role assignments were saved. Click on Continue to go back. Select one or more users in the Select users to assign role field. Select the created role for the Select role field. Select the cohort that was created in Select cohorts field. Click Assign Confirm that you are able to successfully perform the operation.