ORA-20446: The owner of the job is not registered

If you have the following error in EM:

ORA-20446: The owner of the job is not registered ORA-06512: at "SYSMAN.MGMT_JOBS", line 168 ORA-06512: at "SYSMAN.MGMT_JOBS", line 86 ORA-06512: at line 1

It is said to be a bug in  Oracle 11g .

To solve this, you should login as a sys user and run the following command:

execute MGMT_USER.MAKE_EM_USER('USERNAME');