As highlighted in the forums by Sean, Let's Encrypt recently discovered a bug in their Certificate Authority (aka CAA). The implication of this is that some of the certificates that they have issued, they shouldn't have!
Just shy of a year since our v14.1 release I am relieved to announce that Core v14.2 is finally ready for prime time!
It's been a while in the making, but v14.2 Core is now available for immediate launch in the cloud via the Hub. Amazon MarketPlace builds are on the way too, although no ETA at present. (Almost) all of the other builds (e.g. ISO, OVA, Xen, Proxmox etc.) can also be downloaded from the Core appliance page.