adop option cleanup hung forever:

Error:

ORA-04020: deadlock detected while trying to lock object SYS.DBMS_SYS_SQL SQL: begin sys.ad_grants.cleanup; end;


Solution:
Connect to SQL*PLUS as APPS
 SQL>select count(1)
  from dba_tab_privs
  where table_name='DBMS_SYS_SQL'
  and privilege='EXECUTE'
  and grantee='APPS'
If retun row.
Run the following command: "exec sys.ad_grants.cleanup;"

 SQL>select count(1)
  from dba_tab_privs
  where table_name='DBMS_SYS_SQL'
  and privilege='EXECUTE'
  and grantee='APPS'
 
verify 0 rows are returned

Doc id: Adop Cleanup Issue: "[ERROR] [CLEANUP] ORA-04020: deadlock detected " (Doc ID 2424333.1)