I'm getting this:
Mixed Content: The page at 'https://qlik.<xxxxxx>.com/dev-hub/single-configurator' was loaded over HTTPS, but requested an insecure resource 'http://qlik.<xxxxxx>.com/single/?appid=4d1b2520-4d38-4e2c-9a6c-eb085d3ee6cb&obj=HbuLUk&opt=nointeraction&select=clearall'. This request has been blocked; the content must be served over HTTPS.
I hadn't noticed the red x on the shield in Chrome's address bar; if I click 'load unsafe scripts' then the preview works.
Obviously there's an underlying issue here but I'm not sure what I have to do (I've only just begun with the dev-hub)