I had the same issue when testing some code against a newly created scott/tiger demo schema. Scott was missing a number of basic privileges. After granting the privileges below to scott, the error no longer occurred:
GRANT CREATE VIEW to SCOTT;
GRANT CREATE TYPE to SCOTT;
GRANT CREATE PROCEDURE to SCOTT;
GRANT UNLIMITED TABLESPACE to SCOTT;
GRANT ALTER SESSION to SCOTT;
GRANT CREATE TABLE to SCOTT;
GRANT CREATE TRIGGER to SCOTT;
GRANT CREATE SEQUENCE to SCOTT;
GRANT CREATE SESSION to SCOTT;
GRANT DEBUG CONNECT SESSION to SCOTT;
i found a solution, for my case, which is the same error as yours.
at the code line: h1 := dbms_datapump.open (operation => 'EXPORT', job_mode => 'SCHEMA', job_name=> 'budget_exp1', version => '10.1');
change the job_name to something else, because if for some reason the procedure is not running properly, this job name: budget_exp1 got tied up, so when you execute the procedure again, you got the error message, so change that, and exec procedure_name, you should be fine.