We have come across a scenario where a client had edited a final invoice. This is usually accepted within Commusoft, however in this case the Save button was not clickable. This invoice was sent to their accounting package. This was not the problem either because Commusoft will prompt you to edit this in your accounting package too.
The type of edit in this case caused the issue. The client had edited the breakdown type and in this case it is not possible to complete this action after it has been sent to an accounting package. Please credit the invoice, and create a new invoice in the correct breakdown you require.