ora 20001 error in oracle dbms scheduler
Your question contain 2 items that must have been looked at before question itself arose:


Have you looked at API of DBMS_SCHEDULER (any programmer should do that before knowing how to use built-in [package]) ; another words have you RTFM?
Oracle (most of the time) is in-fact very good with "responses" - error signaling back to "client". Have you googled ora - 20001 ?


To your question:


Your job action is NULL; you need to have some procedure that does something AND also is not named as Oracle keyword or PLSQl block that must have at bare minimum begin and end
- docs
Oracle error 20001 is custom error and if you want to see the code you need to contact DBA's.
Based on the message , seems that your schema also missing some grants (you obviously logged in to the database , so message itself is deceiving , but the exact error can only be identified by going thru the code or checking with DBA's directly - see above )
why do you need job id? your job name is providing your with information already! check API's!!