The date was originally incorrectly stated as 17 Dec. This has now been corrected to 16 Dec.
We are aware of, and currently investigating, an issue which is causing customers to experience slow load times, and delayed posting of messages.
Our teams are presently working to resolve the issue and restore Yammer services to normal operation.
A further update will be provided upon resolution, or at 7:00 PM, PST, whichever occurs sooner.
Thank you for your patience during this interruption.