Their status page is broken. You can see the actual issue on the history page instead, or specifically https://letsencrypt.status.io/pages/incident/55957a99e800baa...

    April 14, 2016 12:47PM MDT
    April 14, 2016 6:47PM UTC
    [Investigating] We have noticed an increased number of errors. We are investigating now.

    April 14, 2016 1:21PM MDT
    April 14, 2016 7:21PM UTC
    [Resolved] Systems have fully recovered and all services appear to be operating nominally. Cause seems to have been a transient hardware failure and further investigation is under way.

Or at least the most recent issue... they both marked it as resolved and "further investigation is under way". Should be "investigating/monitoring" instead?