The KBOX seems to require the specification of an LDAP login name and password in order for the scheduling icon to show up. Since our LDAP server does not require a LDAP login/password (all of the relevant user data is visible via anonymous bind), we left those fields blank. When I created a dummy LDAP account just for the purpose of binding, and specified this account for the LDAP login/password, the scheduling icon showed up again.

Ideally it would be good if this limitation could be removed (so that an LDAP login/password is not required to get the scheduling icon to show up). If that's not possible for some reason, it would be good to at least mention this requirement in the documentation, and/or issue a warning popup (e.g. "If you want to schedule user downloads from this LDAP server, KBOX requires an LDAP login/password to be specified"). As it stands, customers have no way of knowing that this dependency exists.