ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired ORA-06512: at "APPS.WF_NOTIFICATION"

Approval Workflow Notification Mailer Error :

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired ORA-06512: at "APPS.WF_NOTIFICATION", line 5130 ORA-06512: at line 1

Solution:

Sql> Select do.owner, do.object_name, do.object_type, dl.session_id, vs.serial#, vs.program, vs.machine, vs.osuser

from dba_locks dl, dba_objects do,v$session vs

where do.object_name ='WF_NOTIFICATIONS' and do.object_type='TABLE' and dl.lock_id1 =do.object_id and vs.sid = dl.session_id;

Issue the command Alter system kill sessions 'Sid, serial#' immediate;