Facebook and associated services, including WhatsApp and Instagram had a global outage that lasted 6 hours. During this time no posts were able to send to Facebook Pages, Facebook Groups and Instagram Business Pages. They will show up as failed in user accounts.
In addition, statistic collection will have failed, and subsequent statistic collection for those posts will not be gathered as we halt any stat collection jobs when we encounter a failure.
Facebook is still reporting a low level of errors on their Graph API, so please expect the occasional post to fail in the next 24 hours.