Membership Not Integrated with the General Ledger:
Do your end of year roll just prior to generating your next years subscriptions.
Procedure:
Backup your data.
From the Membership menu, select Subs End of Year.
Enter the date to which you wish to delete transactions (i.e. 31st October)
Click on the green tick.
Do not interrupt for any reason.
Membership Integrated with the General Ledger:
If your Membership module is integrated with the General Ledger then you cannot roll the Membership module. It is automatically rolled when you do your Financial End of Year.