open dataset exception not triggered

hello folks i'm having a dump because i can't open the dataset, but

when i use this code

open dataset p_file for output in text mode encoding default message mes.

if sy ne 0.

message mess type E.

endif.

the error is triggered but if i use:

TRY.

       OPEN DATASET p_file FOR OUTPUT

            IN TEXT MODE ENCODING DEFAULT.

     CATCH cx_dynamic_check  INTO gr_err.

       gs_msg = gr_err->get_text( ).

   ENDTRY.

in debug i can see sy-subrc = 8 but the catch is not trigger, i have also try with   cx_sy_file_authority but nothing, i'm in ECC6 unicode.

Regards