Hi,
How add listing in main category. No subcategory.
I added main category in admin panel and then publish listing with site, but when publish listing write mistake Category invalid.
How to solved the problem?
Thanks.

@mephistop
You need to allow this function in your oc-admin.

Go to: oc-admin > settings > general
Check here option: Allow users to select a parent category as a category when inserting or editing a listing

This functionality is not recommended for classifieds.