APEX

a page contains Master-Detail, when going to Save data it is showing below error:
1. ORA-06502: PL/SQL: numeric or value error: character to number conversion error
when checked in Console via Inspect it is showing below error in Debug Message Data for all IG columns in the Detail region
2. ERR-1002 Unable to find item ID for item "IL_ITEM_MODEL" in application "130"
how i can check and resolve these errors? please help especially for ERR-1002

regards

code to Save IG data:

declare
v_code number;
begin
   case :APEX$ROW_STATUS
    --------
   when 'C' then -- means Create if its new row
     insert into INV_LN(IL_ORG_ID, IL_TRANS_CODE, IL_TRANS_LN, IL_ITEM_MODEL, 
                IL_ITEM_LOCATION, ITEM_DESC, IL_ITEM, IL_UOM, IL_RULE, 
                IL_QTY, IL_UNIT_COST, IL_REMAKRS, --IL_CRE_BY, IL_CRE_DATE, 
                IL_AMOUNT, IL_UNIT_PRICE)
     values      (:SESSION_BUS_UNIT, :P178_IH_TRANS_CODE, V_CODE, :IL_ITEM_MODEL,
                 :IL_ITEM_LOCATION, :ITEM_DESC, :IL_ITEM, :IL_UOM, :IL_RULE, 
                 :IL_QTY, :IL_UNIT_COST, :IL_REMAKRS, --:APP_USER, SYSDATE, 
                 :IL_AMOUNT, :IL_UNIT_PRICE)
     returning v_code into :IL_TRANS_LN;
   -------- end of create row
 
    when 'U' then  -- means update if exist and any change occured in any row
    UPDATE INV_LN SET
            
            IL_ITEM_MODEL       =   :IL_ITEM_MODEL, 
            ITEM_DESC           =    :ITEM_DESC,
            IL_ITEM             =    :IL_ITEM,
                       IL_ITEM_LOCATION    =    :IL_ITEM_LOCATION,
            IL_UOM              =    :IL_UOM,
            IL_RULE             =    :IL_RULE,
            IL_QTY              =    :IL_QTY,
            IL_UNIT_COST        =    :IL_UNIT_COST,
            IL_REMAKRS          =    :IL_REMAKRS,
            IL_CRE_BY           =    :APP_USER,
            IL_CRE_DATE         =    SYSDATE,
            IL_AMOUNT           =    :IL_AMOUNT 
   WHERE   IL_ORG_ID           =    :SESSION_BUS_UNIT
   AND     IL_TRANS_CODE       =    :P178_IH_TRANS_CODE
   AND     IL_TRANS_LN         =    :IL_TRANS_LN;
   -------- end of update row
    
    when 'D' then  -- means Delete a row if mark to Delete
    delete from INV_LN
     WHERE IL_ORG_ID = :SESSION_BUS_UNIT
       AND IL_TRANS_CODE = :P178_IH_TRANS_CODE
       AND IL_TRANS_LN = :IL_TRANS_LN;
   -------- end of delete row
    
    END CASE;
END;