Firefox has blocked parts of this page that are not secure

Firefox has blocked parts of this page that are not secure started to appear recently.  I tried cleaning up any insecure links, such as http, and yet this message continues to plague.  Tried several WordPress plugins to no avail.  It turns out to be something less sinister. The Firefox version was version 57.  After an upgrade to version 59.  All is well again.

 

secureconnection