The solution for each browser available for use with CAPC are as follows.
Microsoft Internet Explorer
Enable this feature:
Disable the security.mixed_content.block_active_content configuration entries value from true to false:
Note that in FireFox after making that change you may still see this warning in the browser after doing so:
When a page has insecure content, the following shield icon will appear in the address bar (Red Box). Click on it, and select "Load Anyway" or "Load unsafe script". The video or other media will load.
The URL in the address bar will show to indicate that the page is not fully secure, but it will load the content.