I was trying to install DHCP on a standalone server, but although
DNIPINST said that it had upgraded the schema I was unable to create any
objects in the DNS/DHCP console. It turns out that the NDS schema was
corrupt, but even after running DSREPAIR to repair the local database
using the default options I can't load DNIPINST with either the -R or -F
flags; the error message in either case is this:

DNIPINST-6.02-113 : The class DNIP:DNS Zone exists with different
mandatory attributes.

Is there any other way of repairing the NDS schema?