Make sure you are not blocking content.

Diagnose Firefox issues using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}acking-protection-firefox-desktop

I have deleted cookies and cleared the cache several time and it had no effect.

One solution had a method through the Settings menu to allow 3rd Party Cookies, but the steps in the solution did not exist on my (updated) version of Firefox.

Still looking for the answer. rds

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia

If the problem goes away with the computer in Safe Mode, the problem is with one of the other programs on the system.

As a test, disable your protection programs.

Still did not solve the problem. Had McAfee Support on phone & Proxy for 45 minutes. It is not their protection that’s blocking it. Any other suggestions?

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?