I was just adding my first SNMP data source, when I noticed a blinking yellow warning triangle on the page name area (the green bar next to the menu). Hovering over it came up with a popup box saying "Enterprise Version"... Confusingly, sitting still longer on it, the browser popped up the alt-text, which said "Community Version".
See this image (uploaded to an external host because attaching here gave an error): https://ibb.co/byNctv
Clicking the triangle results in a transparent black overlay (not shown in the screenshot), of the type you see when a dialog of some sort should be shown. But there's no dialog. Just the blackness. You can't click anywhere to get out of it. Only going back or reloading the console gets out of it.
It doesn't appear to happen with any consistency. First time was while adding an SNMP module. But the second time was on a different page. And the third time - trying to get the screenshot - it wasn't until I'd clicked around for a few minutes.