Schedules are no longer working and if you look in the latest RmiServer.log or RmiServer<timestamp>.log in the master's $AW_HOME/log directory.
There is the following message:
ErrorMsg: AwE-5001 Database Query Error (10/10/10 1:19 AM)
Details: ORA-20999: Scheduling has encountered an exception - Scheduling will not continue until issue is resolved - [ORA-20001: Submit_chains so_sch_seq=17370--ORA-00001: unique constraint (APWXPROD.SO_JOB_QUEUE_IDX2) violated]
ORA-06512: at "APWXPROD.AW5", line 1984
ORA-06512: at line 1
Log into sqlplus as the Oracle Applications Manager user and run the following sql:
select jt.so_module, sch.aw_sch_name from aw_module_sched sch, so_job_table jt where sch.aw_job_seq = jt.so_job_seq and sch.aw_sch_seq = <seq num>;
Replace <seq num> with the seq from the error message.
This should return a chain name. Then edit the schedule associated with that chain and make a change, apply it, change it back then re-Apply. This should correct the issue by re-ordering the chain and allow scheduling to continue.