HI, are you running any of the following : security software like Avast /AVG, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate which can cause connection issues. Most of these have just updated in the last couple of days or have new versions out.

Most often on each Community Forum for them you can find information such as turning something off or on to fix the issue.

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
• https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites
• https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message
• https://support.mozilla.org/en-US/kb/connection-untrusted-error-message
• http://kb.mozillazine.org/Error_loading_websites

Please let us know if this solved your issue or if need further assistance.

MiazgaSakai said

Safe mode: page and subpages correctly display in safe mode

It could be the work of one of your add-ons, or it could be Hardware Acceleration. How to disable Hardware Acceleration {web link}

Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control> (Mac=<Command>) <Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All Of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.

@Pkshadow No I am not running any antivirus software, its a recently formatted computer only a few weeks old.

@FredMcD As stated in the question I have checked hardware acceleration, which had no effect on the problem and I do not have any add-ons/Extensions or themes installed.

So this so new, please get a installer from here :

• https://www.mozilla.org/firefox/all/

Give the boot to the one that is in there please.

@Pkshadow I'm afraid the new install from the link you provided had the same problem.

I noticed that bookmarks and settings carried over despite the uninstall, this is my first time with a mac. Is there any way to clean this up when you uninstall?

MiazgaSakai said

I noticed that bookmarks and settings carried over despite the uninstall

Firefox comes in two or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

Is there any way to clean this up when you uninstall?

Use these links to create a new profile.

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address bar.