What is your VFP version? In VFP8 this error pretty much meant, that you now need to restore from the backup.

In VFP9 we were able to recover from this error using VALIDATE DATABASE RECOVER.

In any case, before attempting to change RI, always do the following:

1. Make a backup

2. OPEN DATBASE myDATA EXCLUSIVE
COMPILE DATABASE
PACK DATABASE
re-build RI

>After editing referential integrity and trying to save I get the above error message. I have tried VALIDATE DATABASE and I have also deleted the .dcx index file as suggested in the help file and opened up the dbc again when the index is rebuilt, but to no avail. The 3rd Help suggestion ("call Microsoft support") does not fill me with joy.
>
>And to make matters worse, the only way I can then quit VFP is to shut it down in task manager. Groan.
>
>Any help greatly appreciated.
>
>Barry Sutton.