Getting this on about 1-2% of page loads here on xenforo.com, has been happening for about 3-4 weeks now.
Ruled out both connection (happens behind VPN and happened before and after my recent ISP switch) and browser (happens on chrome too, didn't yet screenshot error but it's a totally different message), and happens on a couple of PCs with varying OSes.
Refreshing fixes it instantly.
I haven't had a chance to watch in wireshark to see what is actually happening at the packet level, but it renders the top bit of the page before quickly flitting to that error message.
Anyone else getting this?