No version information received - Subscribe to download

As of today, when I launch Unreal Engine 4 I get the error: No version information received.

From the log, it appears that authentication completes successfully. However, a 500 server error is received when querying:
https://launcher-service-prod06.ol.epicgames.com/launcher/api/buildManifest/launcher/latest?label=Production&platform=Windows

I can hit OK, and open the launcher anyway. The result is that all example content launch and download buttons are replaced with a link labelled ‘Subscribe to download’ which opens the unreal engine dashboard webpage.

My subscription is currently active.

The problem went away after about an hour.