Had this been a OneNote flaw, it would have read:
Microsoft has sent an email to users warning of a critical flaw in multiple version of Microsoft's OneNote that can cause a severe loss of data, the extent of which is not entirely known. Microsoft refuses to acknowledge the severity of this issue, claiming that only "a small number of people" are affected. Those who have received the email may be able to install an update to repair the flaw, but the efficacy of this "fix" has not been confirmed. Regardless of the "fix", the users data has been lost irrevocably. The glitch has been occurring for many months but this is the first response Microsoft has provided.