It is intended to alert you whenever there is both encrypted and non-encrypted displays on a webpage; in the event you were under the impression it was completely ‘private’.
It may merely be a case of some 3rd party advertising (or other “asset”) that is not encrypted, and usually does not mean there is a serious problem.

To circumvent these issues in the future, make the following changes:

INTERNET EXPLORER: Tools> Internet Options> Privacy> Advanced:
here check ‘Override automatic….’; ‘Allow session cookies’; ‘Allow 1st party cookies’ & ‘Block 3rd Party Cookies’.

Firefox: Tools> Options> Privacy> top drop menu set to “Firefox will use custom settings…”> Check ‘Accept Cookies from sites’
►& Un-Check ‘Accept 3rd Party cookies’;
And Tools> Options> Security> Warning Messages heading> Settings button: uncheck the part about showing both encrypted and non-encrypted> OK out.

I don’t use IE , so no advice can I render.

I hope I helped u……