lsmw.conv is not a session record (type 0)

Hi

i am using lsmw to import gl master records. all my steps are correct but on the last step when i have to run batch input session the message below appears:

lsmw.conv is not a session record (type 0)

i have used the method both ticking and un-ticking file without session records but still doesn't work.

can anyone advise as to what the issue could be?

thanks.

Waheed