Sometimes concurrent request completed with below error message : 

Message :Record is currently being worked on by another user,
Please try to update it later.
no. of OE messages :1
Error msg: Record is currently being worked on by another user
interface_header_to_OM failed
InterfaceTripStop: total stops processed: 1
Stops processed for ORDER MANAGEMENT with status NORMAL: 0
Stops processed for ORDER MANAGEMENT with status WARNING: 1
Stops interfaced for ORDER MANAGEMENT: 0

Record lock can be checked
OEXOEORD - 'Record is Currently Being Worked On By Another User' or 'Order Has Been Locked By Another User' (Doc ID 182322.1)

1. Check with users to see if anyone is locking the sales order.
2. Have DBA check for locked sessions on sales order tables.
   For example: oe_order_lines_all and oe_order_headers_all.
   Run the following SQL by logging into SQLPLUS as system/password
   This query will identify which session id's along with their username are
   holding the locks
   
   SELECT SN.Username, M.Sid, M.Type,
   DECODE(M.Lmode, 0, 'None', 1, 'Null', 2, 'Row Share', 3, 'Row
   Excl.', 4, 'Share', 5, 'S/Row Excl.', 6, 'Exclusive',
   LTRIM(TO_CHAR(Lmode,'990'))) Lmode,
   DECODE(M.Request, 0, 'None', 1, 'Null', 2, 'Row Share', 3, 'Row
   Excl.', 4, 'Share', 5, 'S/Row Excl.', 6, 'Exclusive',
   LTRIM(TO_CHAR(M.Request, '990'))) Request,
   M.Id1, M.Id2
   FROM V$SESSION SN, V$LOCK M
   WHERE (SN.Sid = M.Sid and M.Request ! = 0)
   or (SN.Sid = M.Sid and M.Request = 0 and Lmode != 4 and (id1, id2)
   in (select S.Id1, S.Id2 from V$LOCK S where Request != 0 and S.Id1
   = M.Id1 and S.Id2 = M.Id2) ) order by Id1, Id2, M.Request;
3. After record locks are identified, ask DBA to release the record locks.
   Once you identify which sessions are holding the lock..then you can gather
   more info on each of the individual sessions as well by running the following
   query :
   SELECT sid, taddr, lockwait, status, sql_address,
   row_wait_obj# RW_OBJ#, row_wait_file# RW_FILE#, row_wait_block#
   RW_BLOCK#, row_wait_row# RW_ROW#
   FROM v$session
   WHERE sid IN( < values as retreived from the above query>);
   ORDER BY sid;
4. Do you have any personalization on the form or using a folder, any custom code/hook?
   Please go to Help > Diagnostics > Custom Code > Off
5. Confirm that the data is corrected when viewed in the Oracle Applications.
6. If you are satisfied that the issue is resolved, migrate the solution as appropriate to other environments.