1. An invoice can now be paid by "Credit Balance" which includes all unapplied Payments and Credit memos 
  2. If Reseller has documents to pay – invoices and debit memos. They are highlighted on the Home page and in a separate list called “Unpaid documents”.
  3. In the Unified Reseller Control Panel (former CCPv2), the option to unlink Financial documents is no longer available, such as detaching credit memos from invoices and unlinking payments from invoices for financial compliance reasons.
  4.  If a reseller doesn’t like how the system applied his payments/credit memos to open invoices, he can call Modern Support to revert the changes.

To apply or use an open credit memo to pay an invoice, please follow the steps on How to Pay Unpaid Invoices