Enterprise Manager :: Job Submission Failure

am trying to create a backup job in my UAT/testing instance, but with little success. I'm trying to create a backup job to disk (backup is to be stored in a drive local to the DB server) and it seems simple enough, but I keep getting the following error:

The job submission has failed for the following reason

ORA-06502: PL/SQL: numeric or value error: hex to raw conversion error ORA-06512: at "SYSMAN.DECRYPT", line 5 ORA-06512: at "SYSMAN.MGMT_CREDENTIAL", line 408 ORA-06512: at SYSMAN.MGMT_CREDENTIAL", line 1007 ORA-06512: at "SYSMAN.MGMT_CREDENTIAL", line 1400 ORA-06512: at SYSMAN.MGMT_JOBS", line 295 ORA-06512: at "SYSMAN.MGMT_JOBS", line 78 ORA-06512: at line 1

In "Recovery Settings", I have a "Flash Recovery Area Location" defined (path local to the DB -i.e. the server that the DB resides on), a "Flash Recovery Area Size" of 4 defined, and a Flashback Retention Time of 24 hours defined. Everything else is riding default values.

In "Backup Settings", there's nothing defined. Everything here is riding default values. As I understand it, not specifying a Disk Backup Location is fine so long as the Flash Recovery Area is defined. All the local services are turned on (scheduling, etc.).

If it's relevant, I mirrored the recovery/backup settings in UAT to the same as PROD, but changed what I needed to in order to accommodate the UAT environment (e.g. paths, etc.)