> Using Firebird 2.1, the message was changed to:
>
> violation of FOREIGN KEY constraint "@1" on table "@2"
>
> My program was analyzing the error message to extract both foreign key and
> table names, so it can perform a insert to automatically correct this kind
> of error.
>
> Is there a way to make Firebird 2.1 work like 1.5 in this case?

Yes. Clean your FB installation and never use fbclient.dll from
version 1.5 with firebird.msg from version 2.1.

SY, SD.