/SAPDMC/LSM_FILE_INFO_GET with MESSAGE_TYPE_UNKNOWN runtime error

Hi, I can't figure it out why sy-msgty just wouldn't return any value. It just kept on prompting the "MESSAGE_TYPE_UNKNOWN" runtime error, saying that "Only message types A, E, I, W, S, and X are allowed".Please advise, below are the codes.

CALL FUNCTION '/SAPDMC/LSM_FILE_INFO_GET'

EXPORTING

project = p_project

subproj = p_subproj

object = p_object

x_only_used_files = ' '

• IMPORTING

• FILE_READ =

• FILE_CONV =

• PATH_CONV_LOG =

• FILE_CONV_LOG =

TABLES

t_lsoinp = i_file

EXCEPTIONS

no_such_object = 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.