You are getting this error while performing a data pump export (EXPDP) using a dump filename that is already present at the destination.
EXPDP 'user/pwd' SCHEMAS=user DUMPFILE=dumpfile.dmp NOLOGFILE=Y DIRECTORY=expdir
ORA-39001: invalid argument valueDump files are never overwritten (in contrast with LOG files and SQL files generated by the data pump), so you must either change the dump filename in the command line or rename or move or delete the existing file prior to attempting the operation again.
ORA-39000: bad dump file specification
ORA-31641: unable to create dump file "C:\oracle\product\10.1.0\admin\orcl10\dpdump\dumpfile.dmp"
ORA-27038: created file already exists
option specified, file already exists
See a previous posting for other common error situations that you can encounter when performing a data pump export.
See message translations for ORA-31641 and search additional resources