Getting cluster error in luci GUI and not able to administer the cluster

Issue

When I came to look at my cluster configuration on the luci web page, I'm now seeing an error:

An error occurred while attempting to get status information for this cluster. The information shown may be stale or inaccurate.

All of the cluster information is in red and I cannot seem to do any actions on the cluster at all. The cluster nodes themselves seem to be operating normally.

I've tried restart luci, and ricci on all the cluster nodes but that didn't change anything.