Never mind. I restored an older version of the database, upgraded its
schema to the one that was causing me problems and tried backup/restore
again. And it worked. Which is I guess the worst possible outcome,
because I still don't know what caused it but now I can be sure that it
is a random occurence. I'll just keep my fingers crossed that it doesn't
happen with any important databases.

Pepak

> Hi!
>
> I am at a loss what to do now. I have a FB 1.5 database which seems to
> work fine and even passes gfix -validate -full without any complaints. I
> can backup the database using gbak, but if I take that backup and
> immediately restore it (gbak again), after all data and most (not sure,
> maybe all) indexes get restored, I get error "Invalid request BLR at
> offset 752, data operation not supported". After that, the database is
> inaccessible - either because it is shutdown or because it has an
> unsupported on-disk structure of 32779.
>
> I checked and re-checked that I am working with the right database file,
> that the version of database matches that of the server and that of gbak.
>
> I tried to take that backup file and restore it to a FB 2.1 server - and
> it worked correctly.
>
> What could possibly be causing this problem, or what else I could do to
> locate the cause?
>
> Thanks,
>
> Pepak