Hi Gurus,
i have written this code in uncode enabled server,
DATA : BEGIN OF ITAB,        MATNR(20) TYPE C,        TEXT TYPE STRING,        END OF ITAB. DATA : L_TEXT TYPE STRING.  PARAMETERS : P_DSET TYPE STRING.    *OPEN DATASET P_DSET FOR INPUT IN TEXT MODE ENCODING DEFAULT.*  IF SY-SUBRC  0 .  MESSAGE 'error in file opening' TYPE 'E'.  ENDIF.  READ DATASET P_DSET INTO L_TEXT.  WRITE : L_TEXT. 
it give me dump saying "At the conversion of a text from codepage '4110' to codepage '4103':
- a character was found that cannot be displayed in one of the two
codepages;
- or it was detected that this conversion is not supported
_The exception, which is assigned to class 'CX_SY_CONVERSION_CODEPAGE', was not_
caught and
therefore caused a runtime error.
and if i wrote 
OPEN DATASET P_DSET FOR INPUT IN LEGACY TEXT MODE or OPEN DATASET P_DSET FOR INPUT IN TEXT MODE ENCODING NON-UNICODE.
then it work .
what is the possible reason and how can we overcome from it..."