Background task problem with alv grid display

Hello !

I have a problem when executing my program in background.

In foreground I have no problem, my ALV appears. In the background I have a dump.

The current ABAP program "SAPLKKBL" had to be terminated because one of the statements could not be executed.

I use the function module 'REUSE_ALV_GRID_DISPLAY'

  CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'     EXPORTING        i_callback_program      = gd_repid        i_callback_user_command = 'F533_USER_COMMAND'        is_layout               = gd_layout        it_fieldcat             = fieldcatalog[]        it_special_groups       = i_fgroup[]        i_save                  = 'X'        it_sort                 = gd_sort        i_buffer_active         = ' '        i_callback_pf_status_set = 'F534_SET_PF_STATUS'     TABLES        t_outtab                = mytab     EXCEPTIONS        program_error           = 1        OTHERS                  = 2.  IF sy-subrc <> 0.    MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno            WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.  ENDIF.

I don't understand where the problem is. Please help me.

Thank you.