I was hoping someone could help… I’m using the tracking code provided which is a relative protocol url and I’m wondering if someone could help in telling me why this would be picked up as an unsecured resource?
I think this is because your website is in HTTPS and Piwik is being called in HTTP (not secure).
The Piwik tracking code (that you insert in your pages) should detect HTTPS and call Piwik with HTTPS automatically, could you check that your JS code is up to date?