You are now required to add sheets to the site before you can contact users and request sheets.
This is a feature to reduce Leechers who only ask for sheets and don't contribute anything to the community.
We do not require a 1 on 1 exchange. Of course you may not necessarily need any of the sheets that the user who asks for one of your sheets has added to the site, however, this new feature simply helps reduce those unwanted emails from people asking you for a sheet and provide nothing in return.
P.S. The user profile page is also slightly changed to show user's sheets by default.