This does not solve my problem.
Here is the exact error message I am encountering:

gbak: opened file e:\database.gbk
gbak: transportable backup -- data in XDR format
gbak: backup file is compressed
gbak: ERROR: unavailable database
gbak: ERROR: failed to create database e:\database.fdb
gbak: Exiting before completion due to errors

Joseph

> Try adding:
>
> -u <username> i.e. sysdba
> -pa <password> i.e. masterkey