ok i ran the command
gbak -fix_fss_metadata -r -user sysdba -password pass /opt/firebird/fbbackup/stock.fbk /ibdata/stock.fdb

got the following error
gbak: ERROR:file /opt/firebird/stock.fbk is not a valid database

--- In firebird-support@yahoogroups.com, Paul Vinkenoog <paul@...> wrote:
>
> Hi,
>
> >> Ah, that's a known issue. Please read instructions here:
> >>
> >> http://www.firebirdsql.org/rlsnotesh/rlsnotes25.html#rnfb25-compat-metadata
>
> > that site seems to be down for me at the moment
>
> When did you last try? It's up for me, but maybe it's a DNS issue.
>
> Anyway, this is what it says:
>
> Effects of Unicode Metadata
>
> If you have not previously updated text objects within the metadata of your
> databases to be in character set UTF8, restoring a database until V.2.5 will
> fail with "malformed string" errors. To resolve this it is necessary to pay
> attention to the files in the /misc/upgrade/metadata directory of your
> installation and to use the new -fix_fss_data and -fix_fss_metadata switches
> in the gbak command line.
>
>
> HTH,
> Paul Vinkenoog
>