iFrame viewed in Firefox is not working or is blank

Firefox 23 came out with the Aug 6th, 2013 and now by default it has Mixed Content Blocking enabled. 

 

This new change within Firefox could potentially affect any web/scripting customizations using iFrames. (i.e. a blank iframe is seen in Firefox only)(Script HTML portlet with iFrame). 

 

Before implementing the solution below, consult with your IT department.

 

Solution:

This can be temporarily disabled on the page by clicking on the shield icon in the URL. 

Or permanently disabled by:

- Go to the URL about:config

- Search for: security.mixed_content.block_active_content

- Set the value to false