Access to UDF library XYZ is denied by server administrator
You'll get this error when Firebird cannot register or use a function in the UDF library. Possible reasons:
a) The UDF library file does not exists
Check 'UDF' subdirectory of your Firebird installation. Perhaps you installed a new version of Firebird and didn't copy the needed UDF files (.dll or .so) as the installer deleted the old ones.
b) The UDF library files are there, but not readable
Perhaps the user account under which the Firebird is running doesn't have privileges to read the UDF (.dll or .so) files. Firebird should also have privileges the read the UDF directory (both read and execute on Linux), but that's rarely a problem.
c) The access is restricted in firebird.conf
Please check your firebird.conf file for UdfAccess parameter. If you have multiple installations, also check that your server is loading the correct firebird.conf file.
d) The UDF library is not built correctly
If the library is not built (linked, compiled) correctly, the server might give this message when it tries to load it.