OPEN DATASET FOR INPUT IN TEXT MODE ENCODING DEFAULT

Hi Guys,

please i need help.

I am using this command:

OPEN DATASET dbFOR OUTPUT IN TEXT MODE ENCODING  DEFAULT.
   IF sy-subrc NE 0.

and I always get
sy-subrc = 8

db is the directory where the file should be written. I have already put file in this directory in others transation but not manually.

What should I check here.

I have already read others disccusions but I didnt find any help. Thanks.