Oracle Export using EXPDP gives ORA-06512 SYS.UTL_FILE error on Windows 7
I just wanted to chime in and share what got me past this error.  In my case (Ora 11.2.0.3 on Win 7) I found I needed the trailing '\' in my directory path.

Replaced:

CREATE OR REPLACE DIRECTORY dpump_dir AS 'C:\Data\SID'


With:

CREATE OR REPLACE DIRECTORY dpump_dir AS 'C:\Data\SID\'