>>>> 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.
>>>
>>> It is bad idea to use IB with Firebird database ;)
>>
>> Eh? I have no idea what you mean by "IB". Interbase, maybe? But where
>> would you get the idea that I am using any Interbase tools (I don't)?
>
> Because Interbase reads Firebird's ODS 11 as ODS 32779 (0x8000 + 11) and reports error above.

Well, in any case, this computer has never had any component of
Interbase on it.

Pepak