>> Perhaps missing IB_UTIL.DLL ?
>
> Or maybe GDS32.DLL(or FBCLIENT.DLL).

But why would you write UDF that depends on client library ?
Either to connect to database (not recommended to do it from UDF),
or to use some date/time converting routines (that are not much good,
e.g. their precision is only whole seconds iirc).

Ivan