For an overview of the membership plan see IMSLP:Membership Q&A.
For more information on the reasons behind this change, see this announcement on the IMSLP Forums.
Please note that some newly-uploaded scores may only be available after a day or two to non-subscribers.
Do you have full score of Sinfonie Concertante, Op.11 (Winter, Peter von)?
If you have it, please upload it!