Our engineers investigated a problem that was affecting users attempting to post messages to Yammer. This incident began at 07:40am, PST and ended at 03:07pm, PST.
From 08:15am, PST to 10:30am, PST affected users may have been unable to post Yammer messages. If the browser was refreshed, messages affected by this incident would have disappeared from the page. However, affected messages were held in the Yammer posting queue and became visible when the infrastructure returned to a healthy state.
The engineering team are reviewing improvements to a portion of the system responsible for message posting.