sys@ORCL>; def
...
DEFINE _O_VERSION      = "Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options" (CHAR)
DEFINE _O_RELEASE      = "1201000200" (CHAR)

sys@ORCL>; grant read, write, execute on directory scripts_dir to adm;

Grant succeeded.

sys@ORCL>; create table adm.files_xt
  2    (  file_info varchar2(255)
  3    )
  4    organization external
  5    (
  6      type oracle_loader
  7      default directory SCRIPTS_DIR
  8      access parameters
  9      (
 10         records delimited by newline
 11         preprocessor SCRIPTS_DIR: 'list_files.bat'
 12      )
 13      location ('sticky.txt')
 14    )
 15    reject limit unlimited
 16   /

Table created.

sys@ORCL>; select * from adm.files_xt  ;
select * from adm.files_xt
*
ERROR at line 1:
ORA-29913: error in executing ODCIEXTTABLEFETCH callout
ORA-29400: data cartridge error
KUP-04001: error opening file d:\oracle\test\sticky.txt

  ...
  access parameters
    (
       records delimited by newline
       DISABLE_DIRECTORY_LINK_CHECK
       preprocessor SCRIPTS_DIR: 'list_files.bat'
    )