Steps to reproduce
1) Default install OpenAM13.5 - 13.5.0-RC12
2) Realm > Services > Add service > select User
3) Enter preferred timezone (optional but would make sense)
4) Click create > leave DN starting view empty -
5) Click save
Expected outcome - service should save as Administrator DN Starting View is optional value.
Data validation error message for iplanet-am-user-admin-start-dn
and bad request error displayed.
Actually because we initially entered preferred TZ a value was saved - but you will be unable to edit values and save if DN Starting View is empty.