LSMW Problem -> Urgent

Hi Guys,

After I run LSMW 13 steps..A session is created in SM35. When I process this session, LSMW is working fine in the foreground state. But when I run LSMW in background , It showing all the records as errors and the session is not processed.

The error is like " Field xyz is not a input field ".

Basically what I am doing is I have 3 fields namely x , y and z. I am concatenating all the 3 fields x + y + z into a non-editable field xyz and storing in a table.

Is LSMW in background doesn't work if the fields are in disable mode ??