>>This is a database of 379 tables, 212 views, 96 relations - impossible to work this in MODI DATA .
>
>Are there any backups? Even if old, can you rename the production DBC, overwrite with the backup, and REINDEX or similar?
>
>ISTR there used to be GenDBC/GenDBCX tools which you could run against a backup, might help with restoring your production one.

The output of GENDBC simply REPLACES the info in the DBC.RIINFO with the DBC opened as a table. The code is faulty, I would not trust something like

LOCATE FOR ObjectType = 'Relation' AND 'ident_ku'$Property AND 'kunden'$Property AND 'ident_ku'$Property AND ParentID = nObjectID

because $ might catch the wrong part of Property and so on. This is to easy to create havoc.
At least it is an idea.