Could you please share some screen shot,if possible to understand your problem in detail.
Few Check points-
- Check Table Nast - Your billing Document should be in this table.
- Maintain Output manually in billing document and check whether you are getting any error or not.
- If you have configured new table for output determination ,then suggest you to go in change mode of table and double click on fields to activate table fields.
- Have you maintain any determination requirement in your access sequence.
- Check Transaction NACE and check what medium you have maintained 4 or 1 in your condition records.
- Check in transaction NACE for your output type,Have you assign any program apart from RSNAST00.
Regards
Amit