ABAP runtime error in ME2N Transaction

Question

Hi All,
I am getting an ABAP runtime error when i run transaction ME2N and then click on th Account Assignment Button.
This is the error i get.
Runtime Errors         GETWA_NOT_ASSIGNED
Date and Time          06/01/2009 16:35:59
Short text
Field symbol has not yet been assigned.
The section of the code which is creating problem is
2326|*... ... find the row that holds the first requested cell                                   |
2327
loop at ct_stin assigning <ls_stin>
2328
where start_indx le i_start.
2329
l_start = sy-tabix.
2330
endloop.                       "Y6DK065306
>>>>>
if <ls_stin>-filled eq abap_false.
2332
lt_delete_row-low    = <ls_stin>-row_pos.
2333
lt_delete_row-sign   = 'I'.
2334
lt_delete_row-option = 'EQ'.
2335
insert lt_delete_row into table lt_delete_row.
2336
endif.
| 2337|         
the internal table ct_stin is not gettin any data in Runtime.
Can anybody help me out in analysing this.
Saurabh

Answer 1

As I understand you have modify the standard SAP program. The problem is when the internal table
ct_stin does not have data the field symbol <ls_stin> does not have any assign. to correct this 
LOOPAT CT_STIN ASSIGNING <LS_STIN>
WHERE START_INDX LE I_START.
  L_START = SY-TABIX.
ENDLOOP.                                                    "Y6DK065306
Check <LS_STIN> IS Assigned.
IF <LS_STIN>-FILLED EQ ABAP_FALSE.
  LT_DELETE_ROW-LOW = <LS_STIN>-ROW_POS.
  LT_DELETE_ROW-SIGN = 'I'.
  LT_DELETE_ROW-OPTION = 'EQ'.
  INSERT LT_DELETE_ROW INTO TABLE LT_DELETE_ROW.
ENDIF.