Can you post what the page looks like, and any error messages you see?

See also:

• https://support.mozilla.org/en-US/kb/how-does-phishing-and-malware-protection-work

There are no error messages that I can see.

You can check the connection settings.

• Options/Preferences -> Advanced -> Network: Connection -> Settings
• https://support.mozilla.org/en-US/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

You can check for recently installed suspicious or unknown extensions.

You can try to disable hardware acceleration in Firefox.

• Options/Preferences -> General: Performance
  remove checkmark: [ ] "Use recommended performance settings"
  "Use hardware acceleration when available"

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration

It looks a little similar to a red shield button on your toolbar. Does anything happen if you click it? Or right-click it?

It's your Porn Blocker add-on :

https://addons.mozilla.org/en-US/firefox/addon/porn-blocker/

Thank-you for helping all of you. To a non-computer man like me it was very helpful. Have a great long weekend. Sheldon