There should be more error detail in the log /Data/currentlog.config
I tested with a clean install on a new db and all the scripts ran for me, possibly some difference in version of Firbird.
I suggest look at the script file
C:\00WEBSITES\InternalKB\Setup\applications\mojoportal-core\SchemaUpgradeScripts\firebirdsql\2.3.9.9\a_tables.config
maybe try to execute it manually with FlameRobin or whatever query tool you use, and modify it if needed to solve a syntax error, then remove it and visit setup again to continue
Hope that helps,
Joe