Your database has an On-Disk Structure (ODS) version 11.1, but your Firebird version only supports ODS 11.0 or lower. ODS 11.0 is Firebird 2, ODS 11.1 is Firebird 2.1 and ODS 11.2 is Firebird 2.5.
You will need to install Firebird 2.1 or higher (I'd advise to use Firebird 2.5).